I know it's Metzler, but these quotes from Farabee suggests it's something that popped up post-season, maybe while working out:
On Exit Day, Farabee said he declined an offer from USA Hockey to play at the 2022 IIHF World Championship in Finland. His plan was to rest for several weeks and then work on his offseason training program to start preparing for next season.
Asked about his health and the various shoulder issues over the season, Farabee insisted he was OK.
"The shoulder feels good. I think coming back the first time it definitely wasn’t in great shape. Definitely tried to play through it a bit, but I think coming back from the second time, I felt a lot stronger. Ever since then it’s been good. Obviously, it gets a little sore with the schedule. I think playing back-to-backs like that can get a little sore, but at the end of the day, its strength was there. I felt pretty good actually the last few weeks of the season there," Farabee said.
So before attributing blame, I think I'd wait until we know more.