This is pretty clearly going to be an IL stint. Can be very serious depending on severity. Fernando Tatis Jr. had it in 2021 and only missed about 10 days, but ended up requiring surgery after the season. Brian Anderson had it in 2021 and missed a significant amount of time on the 60-day IL, also requiring surgery.
If it's more on the short-term side like Tatis, you could see Perkins. However, if it's much longer than that, I think you're going to see Frelick as the new starting CF in place of Mitchell...