The Blue Jays are bound to add a few relief pitchers this offseason as they look to improve on their middle-of-the-pack bullpen from a year ago. One particular area of need is left-handed relief, with Mason Fluharty, Brendon Little, Justin Bruihl, and starter/long man Eric Lauer as the only relief options on the 40-man roster. One potential free agent option is veteran Caleb Thielbar, who could end up being a difference-maker in Toronto in 2026.

Thielbar has had quite the journey as a major leaguer, initially debuting in 2013 with the Minnesota Twins with an electrifying 1.76 ERA in 49 games, generating 1.3 bWAR. After another successful campaign in 2014, he returned to the Twins to open up 2015. After just five games out of the bullpen, he was curiously designated for assignment. Shockingly, it would be over five years before he would step on a major league mound again.

After minor league stints with San Diego, Atlanta, Detroit, as well as with St Paul in the American Association, Thielbar found his way back to the Twins organization in 2019. By the time the 2020 Covid-shortened season arrived, Thielbar was back like he never left, registering a 2.25 ERA across 17 games as the go-to lefty in the Twins bullpen. He would be a mainstay in Minnesota over the next three seasons, producing a sub-4.00 ERA in each campaign as his strikeout rate soared. His 12.1 K/9 in 2022 remains his career high.

The wheels fell off a bit for the 38-year-old in 2024, appearing in 59 games but producing his only negative war campaign, with a 5.32 ERA and 1.56 WHIP. His BB/9 spiked to 4.6, compared to his career average of 2.9.

After his forgettable final season in Minnesota, Thielbar made his way to the Chicago Cubs to play for just his second major league team in his career. He quickly proved that 2024 was an aberration, appearing in 67 games with a 2.64 ERA and 0.87 WHIP. His strikeouts have declined in every season since his career high in 2022, culminating in an 8.7 K/9 in 2025. The good news is that his walk rate came down in a big way last season (2.00 BB/9), making him one of the best left-handers in the league at preventing baserunners.

The veteran mixes his four-seam fastball with a lollipop curveball, as well as a sweeper and slider. As you can see from the above clip, his over-the-top delivery creates a lot of deception. He’s particularly effective against left-handed hitters, who hit just .161 against him in 2025.

Thielbar capped off his season with an excellent string of games in the playoffs for the Cubs, appearing in five games without allowing a run. He pitched 0.2 innings in each outing except for one, where he completed a full inning. There’s a good chance that on the heels of a dominant playoff performance, the six-foot pitcher may find himself playing for another contender in 2026.

If the Blue Jays decide to upgrade their bullpen, Thielbar may prove to be a savvy pickup. Now in his late 30s, there’s a good chance that there will be mutual interest between him and a contender. The Blue Jays have a promising left-hander in Mason Fluharty and an established arm in Brendon Little, but a veteran southpaw that can be relied on would be a welcome addition, and a likely improvement over the other options available for the club.

Thielbar shares some similarities with Danny Coloumbe, another veteran lefty reliever who could be in play for Toronto this winter. Both would be solid options, but Thielbar may be more coveted given his consistency and success in the postseason. Given his age, a one-year deal would make a lot of sense to provide some stability for the Blue Jays in 2026.