DUSTIN PEDROIA
Best-case scenario: An age-33 season like ’99 Craig Biggio (160 games, 16 HRs, .294/.386/.457, 56 doubles).
Worst-case scenario: An age-33 season like ’05 Mark Loretta (105 games, 3 homers, .280/.360/.347).
ANDREW BENINTENDI
Best: Are you familiar with Fred Lynn’s fine work in 1975?
Worst: The revelation of undiscovered (and probably non-existent) flaw in his swing.
MOOKIE BETTS
Best: An .897 OPS, 31 homers, and spectacular defense in right field. So, a repeat of last season. Seriously, how much better can he get?
Worst: I don’t know, he drops a bowling ball on his foot? Nothing other than injury, honestly. He’s Superman in a world without Kryptonite.
HANLEY RAMIREZ
Best: A duplicate of 2016 in terms of production, durability, attitude, and ability to send Dellin Betances’s fastball deep into the night.
Worst: A duplicate of 2015, including prolonged injury, underwhelming production, and apparent indifference.
XANDER BOGAERTS
Best: A full season of his 2016 first-half performance (.329/.388/.475).
Worst: A full season of his 2016 second-half performance (.253/.317/.412).
JACKIE BRADLEY JR.
Best: A couple more months like last May (.381/.474/.701).
Worst: A couple more months like last August (.198/.274/.377).
PABLO SANDOVAL
Best: He stays healthy and relatively slim, plays steady D, and bats .285-.290 with a bunch of timely hits.
Worst: How could it possibly be worse than last year? He plays two games rather than three?
MITCH MORELAND
Best: 1999 Brian Daubach, with a better glove.
Worst: 2002 Tony Clark, but shorter. (2008 Sean Casey, 2005 J.T. Snow also acceptable.)
SANDY LEON
Best: That last season (.310/.369/.476 in 78 games) proves the true measure of who he is as a player.
Worst: That everything before last season (.187/.258/.225 in 75 games) proves the true measure of who he is as a player.
CHRIS SALE
Best: He matches his standard White Sox numbers – 220 innings, 220 strikeouts, a 3.00-ish ERA – but gets standard Red Sox run support. Result: 22 wins. Minimum.
Worst: The Red Sox marketing department does not run its quirky throwback jersey concepts by him before signing off.
RICK PORCELLO
Best: That he repeats his form of last year (22-4, 3.15 ERA, 2016 Cy Young Award winner).
Worst: That he reverts to his form of two years ago (9-15, 4.92 ERA, 2005 Matt Clement clone).
DAVID PRICE
Best: That he’s healthy. That’s it. Because you’re damn sure going to miss him when Kyle Kendrick (4.72 ERA in Triple A last year) and Henry Owens are divvying up 33 starts.
Worst: That Dr. Andrews changes his opinion.
EDUARDO RODRIGUEZ
Best: 15-plus wins and a sub-3.30 ERA. He has the repertoire to excel.
Worst: Pitch-tipping and creaky knees continue to slow his growth.
STEVEN WRIGHT
Best: That he becomes a workhorse knuckleballer reminiscent of ’05 Tim Wakefield (16-12, 4.15 ERA, 225 innings).
Worst: That John Farrell mistakes him for Dave Roberts again.
CRAIG KIMBREL
Best: The ‘16 K/9 (14.1) and H/9 (4.8) rates stay the same, and the BB/9 rate (5.1) is halved.
Worst: Walk-strikeout-walk-strikeout-homer.
TYLER THORNBERG
Best: He’s what Carson Smith was supposed to be last year.
Worst: He’s what Carson Smith was last year.
DREW POMERANZ
Best: He gets traded to the Padres for Anderson Espinoza. Too mean? OK, then this: His final numbers look something like his combined numbers with the ’16 Red Sox and Padres (11 wins, 3.32 ERA).
Worst: This forearm strain that has him starting the season on the DL becomes more ominous, while Espinoza rockets through the Padres system.
JOE KELLY
Best: That he’s as dominant in a large sample of relief work this year as he was in a small sample last year (14 games, 1.02 ERA, 21 strikeouts in 17.2 innings).
Worst: He’s the same exasperating enigma in relief that he was as a starter.
MATT BARNES
Best: That he pitches to the level of his stuff and has a season with an ERA below 4.00 for the first time.
Worst: That he continues to prove that velocity is a slugger’s friend when it isn’t accompanied by command and movement.
FERNANDO ABAD
Best: He’s Javier Lopez in 2008 (2.43 ERA in 70 games).
Worst: He’s Javier Lopez in 2009 (9.26 ERA in 14 games).
ROBBY SCOTT
Best: He becomes the pitching version of Daniel Nava, an Independent League refugee who helps the Red Sox significantly.
Worst: He pitches for the Red Sox this year like Fernando Abad did last year and ends up summering in Pawtucket again.
HEATH HEMBREE
Best: He adds a wrinkle to his repertoire to help him get out lefties (.858 OPS against, career) like he does righties (.634).
Worst: See above, but vice versa.
ROBBIE ROSS JR.
Best: He becomes ‘13 Craig Breslow (1.81 ERA in 61 games).
Worst: He becomes ‘14 Craig Breslow (5.96 ERA in 60 games).
CHRIS YOUNG
Best: Similar production to last season (.276/.352/.498) but without the injury-related interruption.
Worst: His hamstrings refuse to cooperate and the Red Sox are without one of the better bench bats in the league for a prolonged stretch.
BROCK HOLT
Best: Hits .280 while filling in all over the diamond. Basically, his 2015 season all over again, minus the fluky All-Star appearance.
Worst: Plays way too often because of injury to a superior player, wears down, and hits .250.
MARCO HERNANDEZ
Best: Hits over an extended stretch like he did during a 56-at-bat sample last year (.294/.357/.373).
Worst: Remember Cesar Crespo?
CHRISTIAN VAZQUEZ
Best: That he’s reminiscent of Yadier Molina at age 26.
Worst: That he’s reminiscent of Izzy Molina at age 26.
Follow Chad Finn on Twitter at @GlobeChadFinn.