Which players should Red Sox trade? Here’s a guide

Xander Bogaerts is only worth trading as part of a package for a No. 1 pitcher, writes Peter Abraham.Getty Images

Let’s pause from wondering whether the Red Sox will sign Jon Lester to consider the trade market.

A deep farm system did not rescue the Sox from finishing in last place last season. But trading some of those players could help make the 2015 season into something worth watching.

Cole Hamels, Jeff Samardzija, Johnny Cueto, and assorted other established starters are either available or could be depending on the circumstances. That puts the Red Sox in a position to quickly fix their rotation.

How far should they go in making trades? Here’s an opinion on which prospects should be kept and which can go. Draft picks from 2013-14 are excluded from this assessment.

UNTOUCHABLE: OF-2B Mookie Betts. It was obvious last season that Betts is a special player. So don’t trade him, period. Ten years of Betts being an outstanding player is more valuable than anybody available on the trade market.

BASICALLY UNTOUCHABLE: C Christian Vazquez. Somebody has to catch, so unless the Red Sox obtain a front-line major league catcher via trade, Vazquez would seem pretty safe.

TRADE ONLY AS PART OF A PACKAGE FOR A NO. 1 STARTER: SS Xander Bogaerts, C Blake Swihart. Bogaerts was mishandled last season and it contributed to a poor season. But he is 22 and still has a world of franchise-changing potential.

The Red Sox could trade Bogaerts and replace him in the short term with somebody else until Deven Marrero is deemed ready. But trading him has to be for a sure thing.

Swihart is a 22-year-old switch-hitting catcher with Buster Posey-like athleticism. Even if Vazquez settles in as catcher, Swihart could shift positions and still be an impact player.

KEEP AT LEAST ONE OF THIS TRIO: LHP Brian Johnson, LHP Henry Owens, LHP Eduardo Rodriguez. The three lefties represent 30 percent of the team’s top 10 prospects. Figure out which one you like best and keep him. Last season proved that starter prospects can lose value once they actually pitch in the majors.

Henry Owens went 17-5 with a 2.94 ERA playing for the Red Sox’ Double A and Triple A affiliates last season.Jim Davis/Globe Staff

IF IT HAS TO HAPPEN, IT HAPPENS: OF Manuel Margot, 3B Rafael Devers. The two young Dominican prospects have done wondrous things at the lower levels of the minors. But hoping they develop over the next 2-3 seasons is not worth missing out on Hamels. The Red Sox are not a team playing for 2018.

TRADE FREELY FROM THIS GROUP: RHP Matt Barnes, LHP Drake Britton, C Dan Butler, 3B Garin Cecchini, RHP Rubby De La Rosa, UTIL Brock Holt, SS Deven Marrero, RHP Anthony Ranaudo, 1B Travis Shaw, RHP Allen Webster, RHP Steven Wright. There are varying degrees of value here. But all of these guys can be replaced. Marrero would be tough to deal because of his excellent glove. But the Sox will have to give up talent somewhere along the way.

Will Middlebrooks hit .191 in 63 major league games last season.AP

DO THEM A FAVOR: OF Bryce Brentz, 3B Will Middlebrooks, CF Jackie Bradley Jr. These three players could turn out to be successful big leaguers, especially Middlebrooks and Bradley. But it’s probably not going to happen in Boston given how they’re now blocked. The Sox could warehouse all three in Triple A next season, but eventually something has to give.

A few other Red Sox observations:

■ John Farrell asserted last week that Yoenis Cespedes could play center field next season. If that proves to be the case, the Red Sox will have failed at putting together their roster.

Betts, Bradley, Rusney Castillo, and Shane Victorino are better center fielders than Cespedes.

Cespedes has 75 games of major league experience in center field, but most of that came in 2012. In 600 career innings in center, all with Oakland, his UZR is -18.8 and his defense cost the Athletics 13 runs. He would be a disaster in center and probably in right, too. Cespedes has a terrific arm but he does not track the ball well.

■  Trading Cespedes is an easy call. His value is established and the Red Sox have already replaced him.

But Allen Craig is a tougher call. He is a first baseman and right fielder on a team that has Mike Napoli and a host of outfield candidates. He’s also not a particularly good right fielder, which would be a problem at Fenway Park.

Craig’s trade value is at a low point. He hit .215 last season with startlingly bad on-base (.279) and slugging (.315) percentages.

Craig contends he has recovered from the ligament fracture in his left foot that occurred in 2013. But doubts remain, given his performance on the field. Craig is signed through 2017 and would cost only $5.5 million next season. The Sox might be wise to keep Craig as a bench player and evaluate whether he could become the first baseman in 2016.

■  It passed without much notice when the Red Sox designated Ryan Lavarnway for assignment to make room on the 40-man roster for Pablo Sandoval.

It was a good reminder that prospects are baseball’s most replaceable assets.

Lavarnway made his major league debut in 2011, called up to the majors at the age of 24 to fill in as the DH for an injured David Ortiz. Red Sox officials were proud of the catcher from Yale and boasted that he was better than Jesus Montero, who at the time was a heralded prospect with the Yankees.

Lavarnway hit for average and power in his first four seasons in the minors, but never stuck with the Sox. Jarrod Saltalamacchia became established as the catcher and Lavarnway saw his power fade over time.

Lavarnway hit 77 homers in his first 1,372 minor-league at-bats. He has hit 15 homers in 734 at-bats since. In part of four major league seasons, Lavarnway hit .201 over 97 games and 279 at-bats.

■  Jemile Weeks is still on the 40-man roster. Bet you didn’t realize that.

■  Finally, condolences to the family and many friends of Dick Bresciani, who died over the weekend at the age of 76. “Bresh” started with the Red Sox in 1972 in media relations after spending 11 years at UMass-Amherst in the sports information department.

Bresciani was endlessly loyal to the Sox. and many a reporter benefited from his knowledge of the team and Fenway Park. Bresciani also worked hard to help Jim Rice get elected to the Hall of Fame.

Many of the players you grew up watching stayed in contact with the Sox over the years after they retired because Bresciani helped maintain connections with them. He will be missed.

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