For all the hoopla over the new and improved Boston Red Sox offense, there is an obvious question mark: catcher.

The position has usually been one of stability for Boston. Carlton Fisk took care of most of the 1970s, and Rich Gedman the ’80s.

In the 1990s, Tony Pena caught for four seasons, followed by a group that included Damon Berryhill, Mike Macfarlane, Bill Haselman, Mike Stanley and Scott Hatteberg.

Then Jason Varitek paired with Hatteberg in 1998, and took over the job full time in 1999.

Varitek had been the No. 1 catcher until the last two months of the 2009 season, when Victor Martinez was acquired.

With Martinez now gone to Detroit as a free agent, what remains in Boston?

Varitek, who turns 39 in April, and Jarrod Saltalamacchia, 25, potentially a star, but unproven.

And, as always, there are a crop of catching prospects in the minors. Such groups have been long on promise before, but short in production.

FIRST, A LOOK back to one-time catching prospects:

Ever since the Portland Sea Dogs became an affiliate of the Boston Red Sox in 2003, there has been talk of the “next Varitek” coming to Fenway, via Hadlock Field.

Kelly Shoppach, a second-round draft pick, batted .282 for Portland in 2003. But Shoppach was traded to Cleveland before the 2006 season, in the deal that brought Coco Crisp and Josh Bard to Boston.

Shoppach, 30, peaked with Cleveland in 2008 (.261, 21 home runs), but has retreated since, hitting .214 in 2009 and .196 last year with Tampa Bay.

Alberto Concepcion looked Vartitek-like when he caught for the Sea Dogs in 2005. But his numbers faded to .227 in 2006.

For the Sea Dogs’ championship run in 2006, Concepcion found himself the No. 3 catcher, behind Dusty Brown and newly acquired George Kottaras.

Concepcion asked for his release after that year, played two seasons, in the Dodgers’ and Marlins’ organization, and is out of affiliated baseball.

Kottaras, now 27, was given a shot as the Red Sox backup in 2009 (hitting .237), was then released and became the Brewers’ No. 2 catcher last year.

Brown, 28, has always been the odd-man out and caught for Triple-A Pawtucket for the past three seasons. When the Red Sox took him off the 40-man roster in the offseason, Brown signed with the Pirates.

There have been other prospects drafted high, or signed with big bonuses, including Jon Eagan, Ty Weeden and Jon Still.

Eagan did little and retired in 2008, Weeden was released last April, Still left baseball after spring training last year.

THE CURRENT catching situation centers on Saltalamacchia, once a prime-time prospect (Atlanta Braves’ first-round pick in 2003).

Saltalamacchia made his major league debut for Atlanta on his 22nd birthday (May 2) in 2007. The Braves made a (failed) push for the playoffs that year and traded Saltalamacchia to Texas in a deal for Mark Teixeira.

After 47 games for the Braves, Saltalamacchia played 46 for Texas. It would be his most productive year, hitting a combined .266 with 11 home runs.

Because of injuries or poor performance, he never played as many games, or hit so well as his rookie year.

Still, Boston has apparently always liked Saltalamacchia. When the Red Sox inquired two years ago about a trade, the Rangers reportedly wanted Clay Buchholz. No deal.

Texas’ patience with Saltalamacchia ran out last season and he was dealt to the Red Sox for three lower-level minor leaguers (i.e., non prospects).

There have been questions about Saltalamacchia’s defense, throwing ability and offense. But the Red Sox appear ready to hand the catching job to him.

Varitek will serve as the mentor and backup. Chances are he will get most of Josh Beckett’s starts (if Beckett gets his way), and would likely play against left-handers.

While both catchers are switch-hitters, Saltalamacchia hits right-handers better than left-handers (.273/.206), while Varitek hits lefties better (.279/.259).

THE FUTURE behind home plate at Fenway Park may be in Pawtucket or Portland this year.

Mark Wagner, 26, is entering his third year on the 40-man roster, meaning that he will be out of options after this season.

Defensively sound because of his quickness, Wagner needs to prove himself. After batting .301 for part of the 2009 season, Wagner has struggled in Triple-A.

He batted .214 in 42 games in Pawtucket in 2009, and then .205 in 36 games last year. His season was cut short by a broken hamate bone in his left hand.

Luis Exposito, 24, caught the last 1 1/2 seasons in Portland. He hit .260 last year with 11 home runs and 94 RBI. He should start the year in Triple-A.

Exposito, who was added to the 40-man roster this offseason, has a strong arm and is improving defensively.

Ryan Lavarnway, 23, may be the weakest defensively of the four, but the Red Sox say he is dramatically improving.

Offensively, Lavarnway hit a combined .288 with 22 home runs and 102 RBI in Class A Salem and Portland. Fluke year or start of a stellar career? The spotlight will be on Lavarnway.

Tim Federowicz, 23, appears the most polished defensively, but also has further to come on offense, having slipped to a .253 average in Salem last year.

And if none of those four work out, there is an underdog story brewing in Salem. Dan Butler, 24, was not drafted out of the University of Arizona in 2009. Boston signed him that July.

Last year, Butler hit a combined .315 in low Class-A Greenville and then Salem.

Other prospects will work their way up.

And when a Wagner, Exposito, Lavarnway or Federowicz is ready for the majors, say by 2012, what job will be available?

Will one of them serve as Saltalamacchia’s backup or his replacement?

Staff Writer Kevin Thomas can be reached at 791-6411 or at:

kthomas@pressherald.com