Role
Guerrero spent 2026 as a setup man nobody saw coming. Boston signed him to a minor-league deal on Jan. 9, after he'd spent years out of the majors, and selected his contract from Worcester on May 22. He finished with 19 holds in 40 games, his first big-league innings since 2019. He goes into 2027 as one of the right-handers who gets the ball before the closer.
Outlook
The stuff is real. His sinker averaged 100.2 mph per Statcast, topped out at 103.6, and he threw it 85.5% of the time. The bigger change is the strike-throwing: 8 walks in 40.2 innings, after 36 in 46 innings with Miami in 2019. He had a 3.10 ERA and a 1.11 WHIP, and in June and July combined he allowed 2 earned runs in 19.2 innings. The shoulder is the problem. He went on the IL on Sept. 1 with inflammation, came back on Sept. 20, and went back on with a strain three days later. He didn't pitch in the Wild Card Series. He turns 36 in January.
Our take: we'd trust him in a big spot right now. Plan on 45 appearances, though, and don't count on 60 from a 36-year-old throwing 100 with a shoulder strain on the books.