Chen has been pitching through a partial tear in the UCL of his left elbow since the end of 2016 and has been receiving special treatment after each start to help manage it, Tim Healey of the Sun-Sentinel reports.

He hit the DL last July and didn't return until September with what was described at the time as a sprain, but it appears the injury was a little more serious than that. Masahiro Tanaka has been pitching through a similar condition for the last couple of years, so it's entirely possible for Chen to be successful despite the tear provided it doesn't get worse, and he certainly looked fine in tossing seven no-hit innings against the Mariners in his last start. This news doesn't drastically alter his value in re-draft formats, but it does make the veteran lefty a riskier investment in keeper and dynasty leagues.