Nationals ace Max Scherzer impressed his manager, Dave Martinez, during a 48-pitch session Wednesday. Alex Brandon/Associated Press

As Major League Baseball cautiously tiptoes closer toward beginning its delayed 2020 season, several teams welcomed back players who might have been exposed to the coronavirus and the San Francisco Giants resumed workouts Wednesday after finally receiving the results of COVID-19 tests administered over the weekend.

The San Diego Padres, however, revealed that newly acquired infielder Jorge Mateo’s intake test for coronavirus came back positive and he’s experienced symptoms. Mateo was acquired last week from Oakland for a player to be named or cash in the first trade since the transaction freeze was lifted.

Padres Manager Jayce Tingler said Mateo has not been to the ballpark and is self-isolating.

San Diego announced last week that outfielder Tommy Pham tested positive for coronavirus and was asymptomatic. He has not yet rejoined the team.

In Boston, third baseman Rafael Devers practiced at Fenway Park for the first time since the Red Sox opened summer camp. Devers and an unspecified number of other players were working out at nearby Boston College and have since tested negative three times.

When tests reveal “pending” or inconclusive results, the Red Sox have decided to keep those players out of full-team workouts – even if a player hasn’t had a positive test.

“We have to be overly cautious,” Manager Ron Roenicke said.

Devers batted .311 with a league-leading 54 doubles, 32 homers and 111 RBI in 2019. He is scheduled to get a few at-bats when the Red Sox hold their first intrasquad scrimmage on Thursday.

The Giants, meanwhile, resumed workouts at Oracle Park after receiving test results from Saturday, all of which were negative for players and staff. A delay in receiving the outcome of those tests forced the club to cancel practice Tuesday.

Devers wasn’t the only player in the big leagues to get a late start joining the team.

Texas Rangers first baseman Ronald Guzman was on the field Wednesday after missing the first five days of workouts. Although he was at the facility, he wasn’t cleared for workouts while still going through intake testing.

The only Texas players still not cleared to participate are right fielder Joey Gallo and left-hander Brett Martin, both of whom tested positive for coronavirus.

In Cleveland, outfielder Franmil Reyes was cleared by the team’s medical staff to return to the field after being isolated because he attended a party over the July 4 weekend.

The Indians kept Reyes away from Progressive Field after he went to a holiday gathering without wearing a mask. The Indians learned of Reyes’ off-field actions on a social media posting.

Manager Terry Francona said Reyes was retested and can now participate in the team’s training camp.

Also, Indians outfielder Delino DeShields Jr., who tested positive for the COVID-19 virus, is traveling to Cleveland after he had one negative test. He will be tested again when he arrives.

“He was obviously excited. Said he was planning on traveling like the Michelin Man today through the airport,” Francona said.

DeShields is in his first season with the Indians, who acquired him in December from Texas in the trade involving ace Corey Kluber.

In Oakland, right-hander Mike Fiers returned to the field for workouts after being delayed by what Manager Bob Melvin referred to as a “pending issue,” which wasn’t injury-related. Fiers pitched his second career no-hitter last season and was the whistleblower in the Houston Astros’ sign-stealing scandal last fall.

The defending NL champion Astros were without infielder Alex Bregman on Wednesday because his test results were delayed.

“He’s probably frustrated because I know how hard Alex works and how dedicated he is to getting off to a good start,” Manager Dusty Baker said. “There’s nothing that we can do about it.”

Pittsburgh Pirates reliever Hector Noesi has opted out of the season after speaking with his family. The 33-year-old, who pitched for Miami last year, was attempting to make the team as a nonroster invitee. Pittsburgh Manager Derek Shelton said closer Keone Kela has yet to practice with the team but declined to elaborate on the reason for Kela’s absence.

The Cubs have thus far avoided any positive tests, a development outfielder Kyle Schwarber insists cannot be attributed to mere luck.

“You see some names around the league who have got the virus and you’re surprised, and to see the way that we haven’t had any tests come back positive, I mean, that’s unbelievable,” Schwarber said. “I think it’s just a testament to what our guys did off the field taking this serious, knowing that we can do something special here and we’re going to need every single guy in it at the end of the day.”

With the start of the season just over two weeks away, several teams held intrasquad games as the next step in gearing up for the real thing.

Washington ace Max Scherzer threw 48 pitches at Nationals Park and made quite an impression on Manager Dave Martinez.

“We wanted to keep him at 50 (pitches), three full innings, but he looked good,” Martinez said. “The key now is his turnaround. Let’s see how he feels (Thursday).”

Carter Kieboom, the rookie who’s the favorite to replace Anthony Rendon at third base for the defending World Series champions, said it was his first time facing Scherzer since spring training in 2018.

“Same outcome as today,” Kieboom said. “I struck out.”

Tampa Bay’s Charlie Morton allowed two runs and four hits over four innings in a simulated game at Tropicana Field. Lefties Blake Snell and Ryan Yarbrough and right-hander Trevor Richards also pitched.

“It was nice to get the guys in the box, get them some live looks and also try to ramp up the intensity,” Morton said.

In Atlanta, former Sanford Mainer Adam Duvall launched his bid for a starting job when he hit a two-run homer to highlight the Braves’ first controlled scrimmage. Duvall’s odds at grabbing a spot in the outfield improved after Nick Markakis decided to sit out the season due to concerns about the coronavirus pandemic.

The Detroit Tigers had their first intrasquad scrimmage at Comerica Park. The crack of the bat and pop of the ball hitting the mitt were often the only sounds on a scorching afternoon.

“We’re just happy we got back on the field,” Tigers Manager Ron Gardenhire said.

The Orioles were poised to hold an intrasquad game under the lights at Camden Yards without shortstop José Iglesias, who has a sore back.