Red Sox move lefty Martin Perez to bullpen

The Red Sox are bumping Martín Pérez to the bullpen, manager Alex Cora told reporters (including Steve Hewitt of the Boston Herald). Righty Tanner Houck is the favorite to take his place in the starting rotation.

Pérez has been a regular member of Boston’s starting five for the past two seasons. He started 12 games in last year’s truncated campaign and has made 22 starts this season. The southpaw has reliably taken the ball on a regular basis, but he’s posted below-average results throughout his tenure in Boston. Pérez worked to a 4.50 ERA/5.43 SIERA in 62 innings last season, posting subpar strikeout and walk numbers in the process.

The southpaw did at least excel at avoiding damaging batted balls last year, however, holding opponents to an average exit velocity of 86.3 mph and a hard contact rate of a tiny 29.2%. That seemingly played into Boston’s decision to bring Pérez back on a $5 million guarantee, but his contact suppression skills haven’t carried over into 2021. Hitters are making solid contact on a lofty 42.3% of batted balls against him this year, the worst rate of his career. To his credit, Pérez has made some improvements in his strikeout and walk rates, but the more authoritative contact he’s giving up has contributed to an underwhelming 4.77 ERA over an even 100 frames.

Pérez will now transition into role in the bullpen, where he’ll add another lefty to a group already including Josh Taylor and Austin Davis. Pérez has been better against left-handed hitters (.246/.333/.386) than righties (.284/.352/.475) over his time in Boston, so perhaps a situational role could serve him well. It does seem likely to come at a financial cost, as Pérez’s deal contains $100,000 bonuses for reaching each of 130, 140, 150, 160 and 170 innings pitched. A bullpen move will make it difficult for him to reach even the lowest of those thresholds down the stretch. The contract also contains a $6 million club option for 2022 that seems likelier to be bought out.

Houck has made six appearances (including four starts) in the majors this season. The 25-year-old has tossed 22 innings of 2.45 ERA ball, striking out hitters at an elite 33.7% clip while walking only 5.6% of opponents. Houck has posted similarly strong strikeout and walk numbers over six starts with Triple-A Worcester, although he’s been tagged for a less impressive 5.14 ERA in the minors. Between his strong peripherals at that level and quality results in his brief big-league time, the former first-round pick has earned a more regular run in the MLB rotation.

The shakeup comes at a pivotal time for the Red Sox, who entered play Friday night with a 64-46 record. Boston trails the Rays by 1.5 games in the AL East, and the Red Sox are 2.5 games up on the Athletics for the American League’s top wild-card spot. Houck is expected to take the ball Saturday afternoon against the Blue Jays, who trail Boston in the standings by five games.