The list is thinning. The once-bountiful Boston Red Sox farm system is not loaded with sure-bet prospects.

We witnessed that last year when our annual list of Boston’s Top 30 prospects was full of guesswork and maybes. Of that 2017 list, only 16 return. And before you credit Trader Dave Dombrowski, only three of our Top 30 were traded. One became a regular in the majors (Brian Johnson). The rest of the non-listed players are either no longer in the organization or were dropped from our list.

The number of published prospect lists are growing. Baseball America, mlb.com and soxprospects.com are among standards for Red Sox fans (I even write one for a magazine).

For the Maine Sunday Telegram Top 30, we view matters from our porch in Portland, where prospects arrive on the Double-A scene. We consider major league readiness among the factors. That is why little-known Jalen Beeks was No. 3 on our list last year. He reached the majors in June, then was traded in the crucial deal for Nathan Eovaldi.

Two first-round draft picks, pitcher Jay Groome and corner infielder Triston Casas, are highly regarded in other prospect lists for their potential. But Groome is coming off Tommy John surgery and Casas was playing in high school last season.

They’re included here but cautiously down the list.

We also don’t worry if a player has exceeded rookie status. If he has not established himself as a consistent major leaguer, he’s eligible for our prospect list.

Here’s our Top 30, listing their rank (their rank last year), age and position:

Michael Chavis has dealt with injuries and off the field problems (he was suspended 80 games for a positive test for steroids), but he has top-level talent. Staff photo by Derek Davis

1. Michael Chavis (1), 23, Infield

Chavis returns to the No. 1 position. Chavis has been susceptible to injuries (a wrist injury kept him out of the Arizona Fall League) and the 80-game suspension for a positive test for steroids last year created doubts among some. But he is still a top talent (.298/.919 OPS in 46 games last year) and was just added to the 40-man roster. A corner infielder, Chavis may see time at second base next year in Pawtucket.

2. Darwinzon Hernandez (NR), 21, LHP

A lefty with a mid-to-high-90’s fastball, Hernandez was also just added to the 40-man roster. A starter in Salem, he pitched out of the bullpen in Portland for five games and in the Arizona Fall League. In 1081/3 innings he struck out 154 and walked 72. He will start in Portland next year with Fenway not far away.

Bobby Dalbec hit 32 home runs last season (split between Salem and Portland). He also struck out 176 times. Staff photo by Shawn Patrick Ouellette

3. Bobby Dalbec (14), 23, 3B/1B

Dalbec has a mighty swing. He can crush it (32 homers last year in Salem and Portland) and he can miss (176 strikeouts). In the Arizona Fall League he batted .219/.791 (three homers in 73 at-bats and 32 strikeouts). Dalbec played some first base last year (a spot he played a little in college). His offensive potential is enormous.

4. Tanner Houck (9), 22, RHP

The Red Sox challenged the 2016 first-round pick with an assignment to Salem. He had struggles in the first half (5.50 ERA, 41 walks) but finished with an impressive second half – 3.13 ERA, 70 strikeouts/19 walks in 63 innings). One reason for the improvement was Houck going back to his dynamite two-seam fastball. He will start in Portland next year.

5. Mike Shawaryn, 24, RHP

His combined Portland/Pawtucket stats featured a 3.44 ERA, 1.13 WHIP and 132 strikeouts/38 walks in 149 innings. His 93 mph fastball and slider developed. He continued in the Arizona Fall League (2.13, 15 strikeouts/four walks). Shawaryn’s best stuff was early in games. A full season in Pawtucket may determine his role as a starter or reliever.

Travis Lakins moved to the bullpen in 2018 and it revived his career, which was threatened by two elbow stress fractures. Staff photo by Shawn Patrick Ouellette

6. Travis Lakins (NR), 24, RHP

A move to the bullpen resurrected Lakins’ career, which was threatened by two elbow stress fractures. Coming out of Portland’s bullpen, he recorded a 0.86 ERA/0.71 WHIP and 22 strikeouts in 21 innings. In Pawtucket, more of the same (1.65/.0.98, 15 strikeouts). A full season as a reliever could find him in Boston.

7. Bobby Poyner (11), 25, LHP

A deceptive fastball and plus change-up had Poyner surprisingly make the major league roster out of spring training. He was used sparingly and spent most of the summer in Pawtucket. He put up good numbers in 22 innings (1.12 WHIP, 24 strikeouts/three walks). His success will depend on facing batters who have adjusted to his deception.

8. Bryan Mata, (10), 19, RHP

Mata moves up the list despite a sore back shutting him down in late July. He again was the youngest player in his league – starting with Salem when he was 18. With a mid-90’s fastball and solid secondary pitches, he still lacked command (61 strikeouts/58 walks in 72 innings). He returns to Salem, with Portland in his sights.

9. Jay Groome (2), 20, LHP

Still considered Boston’s top pitching prospect, Groome has battled injuries, the last requiring Tommy John surgery before he pitched an inning last year. He will miss most of 2019 and the Red Sox are sure to be cautious with his return. If he still shows his stuff, Groome should be in Portland in 2020 and back on track.

10. Triston Casas (NR), 18, 3B/1B

Drafted 26th overall, with a $2.5 million signing bonus, Casas’ potential as a power hitter has Red Sox fans excited. He made five plate appearances in the Gulf Coast League before thumb surgery ended his first professional season. Drafting high school home run hitters is risky, but Casas, at 6-foot-4 and 240 pounds, has the tools worth the risk.

Tzu-Wei has spent time with the Red Sox in both 2017 and 2018. The 2019 season is his last with minor-league options. Associated Press/Charles Krupa

11. Tzu-Wei Lin (4), Utility

Lin came from nowhere in 2017 to prove he could be a dependable utility player while batting .268 in 25 games. In 2018 he hit .246 in 37 games, while manning second and third base, and center field. He’s also solid at shortstop. This next season will be Lin’s last with minor league options. He could be a major league keeper by 2020.

12. Alex Scherff (12), 20, RHP

In 2017, Scherff was pitching in high school. In 2018, Scherff skipped the rookie leagues and was challenged with an assignment to low Class A Greenville. He struggled at first and seemed to settle down before a rib muscle strain shelved him for two months. He returned for four starts (1.50 ERA) and looked even better.

13. C.J. Chatham (NR), 23, SS

After an injury-plagued 2017, Chatham had a breakout year in Class A (.314/.738) and will be the Sea Dogs’ starting shortstop next year. A second-round draft pick in 2016, his performance in Double-A will tell a lot.

14. Durbin Feltman (NR), 21, RHP

Considered the most major league-ready player in the 2018 draft, the Red Sox took him in the third round, but didn’t rush him despite his dominance (36 strikeouts/five walks in 23 innings). Portland’s closer in 2019.

15. Denyi Reyes (NR), 22, RHP

Even though he dominated in Greenville (1.89 ERA, 122 strikeouts), the Red Sox didn’t promote him until August. Now on the 40-man roster, Reyes will see Portland soon in 2019.

Josh Ockimey hit 20 home runs in 117 games with the Sea Dogs and the Pawtucket Red Sox last season. Staff photo by Derek Davis

16. Josh Ockimey (21), 23, 1B

There were times when Ockimey seemed on the fast track but he needs consistency. Powerful (20 homers in 117 games in Portland/Pawtucket), Ockimey was also streaky. He struggled in the Arizona Fall League (.172, one home run).

17. Chandler Shephard (16), 26, RHP

The Red Sox made an intriguing move, putting Shepherd in the Pawtucket rotation in his first year on the 40-man roster, He had ups and downs (3.89 ERA), and could develop into a reliable call-up next year.

18. Matthew Gorst (NR), 24, RHP

A 12th-round draft pick in 2016, Gorst took off this year with a dominant cut fastball. He reached Pawtucket after a 1.59 ERA in Salem and 0.00 in Portland (20 innings).

19. Antoni Flores (NR), 18, SS

Flores is high on nearly everyone’s rankings because of his defense and offensive potential. He received a $1.4 million signing bonus but turned 18 only last month.

Sam Travis signed with the Red Sox after his junior year at Indiana. He had a strong 2015 but has yet to burst onto the scene. Gabe Souza/Staff Photographer

20. Sam Travis (8), 25, 1B/OF

Travis hit .300 in Portland in 2015 and later had some eye-opening spring training games. But it has not translated in the majors (.250/.663 in 52 games) or even Triple-A (.258/.677 last year).

21. Jarren Duran (NR), 22, 2B/OF

A seventh-round draft pick last year, Duran is someone to watch. He batted .357 in 67 games in Lowell and Greenville with great speed (23 stolen bases and 11 triples).

22. Josh Taylor (NR), 25, LHP

Acquired from Arizona in the Deven Marrero deal, Taylor showed stuff in Portland with a fastball and solid curve. His results were up and down. Taylor, put on the 40-man roster, will be in Pawtucket.

23. Marco Hernandez (6), 26, utility

He broke out in Portland in 2015, contributed in the majors for parts of 2016 and 2017, but has been out with injuries the last 11/2 seasons.

Sea Dogs pitcher Austin Maddox kept the Binghamton Rumble Ponies scoreless until the 9th inning when Binghamton scored twice. Staff photo by Ben McCanna

24. Austin Maddox (5), 27, RHP

After a promising major league debut in 2017 (0.52 ERA in 13 games), Maddox was limited to rehab games last year until finally undergoing shoulder surgery. He will likely miss all of 2019.

25. Brandon Howlett (NR), 19, 3B

He could be the sleeper of the 2018 draft. A 21st-round selection out of high school, Howlett hit .307/.930 in the Gulf Coast League and could be challenged in Greenville next year.

26. Matthew Kent (NR), 26, LHP

Watching Kent is watching a chess game on the diamond. He throws seven pitches (counting sidearm deliveries with the fastball and slider) and turned in a 3.58 ERA. He likely returns to Portland next season.

27. Kyle Hart (NR), 25, LHP

Hart’s fastball climbed into the 90’s this year in Portland and he recorded a 3.57 ERA. He would enjoy a run of impressive starts, then throw a clunker. Another year in Portland seems in order.

28. Dedgar Jimenez (20), 22, LHP

Jimenez was the third of the crafty lefties for the Sea Dogs last season. He seemed to cruise in games, then give up the big inning. His ERA was 4.39. Hadlock Field beckons.

29. Roniel Raudes (25), 20, RHP

Still young, Raudes was in his second season with Salem (3.67 ERA in 11 starts) until he was shut down with elbow inflammation in early June.

30. Nick Decker (NR), 19, OF

Boston spent its second pick of the 2018 draft on another high school power hitter. Another high risk/high reward selection.

From last year’s list

One reached the major leagues – Brian Johnson (11).

Three were traded – Jalen Beeks (3), Ty Buttrey (23) and Williams Jerez (26).

Three were waived or released – Ben Taylor (15), Kyle Martin (24) and Jeremy Barfield (29).

Two are free agents – Justin Haley (17) and Aneury Tavarez (27).

Five were dropped from the list – Jake Cosart (18), Danny Mars (19), Cole Brannen (22), Hildemaro Requena (28) and Jake Romanski (30).

Kevin Thomas can be reached at 791-7411 or:

[email protected]

Twitter: @ClearTheBases