I sustained a rotator cuff tear on day 2 of 16 while rowing a raft down the Grand Canyon. I was able to row ok after that though there were a couple positions with the oars I just couldn't handle. I forget now what the diagnosis was, I think a grade 2 tear but with rehab and over time it isn't a factor at all now. I ended up getting a cortisone shot and doing PT for it. It's been 3 years now so it is as good as it is going to get. Good luck with yours.