Kodai Senga was one of baseball's biggest breakout pitching stars in his MLB debut season, but his chances of following that up in 2024 took a big hit Thursday as the Mets announced he has been shut down at the start of spring training with a shoulder injury

Senga complained of arm fatigue after throwing off a mound early in spring, and an MRI taken on his right arm revealed a moderate capsule strain in the back of his right shoulder. Surgery is not expected to be necessary for Senga at this point, but president of baseball operations David Stearns did acknowledge, "we don't expect Opening Day." 

For his part, Senga told reporters he can still throw in the upper-90s despite the injury, but couldn't perform at his highest level despite it. That would seemingly suggest this isn't a terribly serious injury, but you can't just take a player's word for it. What we've got right now is a pitcher who looked like a potential ace after a very good rookie season, but with enough limitations -- iffy control/command, limited volume -- that he was being pushed down to SP20 in FantasyPros' consensus ADP.

And he's going to drop a lot more than that now. It's possible this injury ends up being a relatively minor issue in the long run, and Senga is able to return not long after Opening Day after resting. In that case, Senga could still end up being a really valuable pitcher for Fantasy -- remember, he struck out 202 hitters with a 2.98 ERA in just 166.1 innings last season. But you can't just assume the best-case scenario here, especially with a pitcher who did miss time during his career in Japan with shoulder issues.

The worst-case scenario here is obvious: Senga just doesn't pitch this season, either because the injury is worse than expected or he suffers some kind of setback while working his way back. That outcome is now on the table, but it's not the only way his season could be derailed by this injury. He's also missing key prep time for the season, and there could be risk that he rushes back, suffers a setback, or just never gets right despite being on the mound. 

Senga was already a fairly high-variance option among the SP2 crowd -- he was very good last season, but was a pretty fringe Fantasy option for the first couple of months as he struggled with walks, so regression risk was always present. And, a minor issue with Senga's profile is that the Mets were already planning on having him throw every six days instead of every five days -- he threw with four days of rest just three times last season. Volume was always going to be a limitation for Senga, even before we knew he was going to miss the start of the season. 

Now, you've got this injury to worry about, on top of very real performance concerns. It's a lot to overcome, and I think it requires dropping him quite a long way in the rankings. I had him as my No. 18 SP in my Roto rankings before, but I'm dropping him to SP42 now, just behind Walker Buehler, another pitcher with volume concerns who is going to have a delayed start to the season after missing last season recovering from Tommy John surgery. We don't know what Buehler will look like after a second Tommy John surgery, which is a real risk factor, but he's also currently healthy, something we can't say for Senga. Both have ace upside, but with big enough question marks that there's just too much risk to make them a central part of your rotation plans. 

It could all work out for Senga, of course, and moving him down this far may look like an overreaction. But he has to be viewed as a significant risk for Fantasy, and one I won't be touching until the double-digit rounds in Fantasy drafts.