Danny Duffy, the veteran left-handed pitcher who CBS Sports ranked as the 36th best free agent available this winter, underwent surgery in October to repair the flexor tendon in his throwing arm, according to Andy McCullough of The Athletic.  

As a result of the operation, Duffy expects to be sidelined until June, or about 11 months from his last in-game appearance. He also told McCullough that he had weighed retiring, but that he's "full-go" for playing, and that he anticipates pitching out of a bullpen for the duration of 2022 before then returning to the starting rotation beginning with the subsequent season. 

Here's what CBS Sports wrote at the time of Duffy's free-agent ranking:

Duffy is a wild card in more ways than one. He didn't pitch after July 16 because of a left flexor strain. That same injury had sidelined him earlier in 2021, and this time it wiped out the rest of his season, preventing him from making an official appearance with the Dodgers following a deadline trade. Duffy is both younger (nearing 33) and better (105 ERA+ since 2018) than most would expect. His fastball fits the modern parameters, in that he gets deep extension on it and induces good vertical break. An adventurous club might sign him with an eye on tweaking his pitch mix to optimize his performance. At minimum, he has experience in both the rotation and the bullpen and could prove to be a value addition if his arm holds up heading forward.

Duffy has appeared in parts of 11 big-league seasons, with all of his in-game outings coming as a member of the Kansas City Royals organization. For his career, he's accumulated a 3.95 ERA (110 ERA+) and a 2.43 strikeout-to-walk ratio.