Do you mean that you aren't as strong post-op but that could be because you used to try harder? Or that you are less strong now but tend to try harder so it isn't that noticible?
Is this what they call the Popeye injury. If so I did mine about 20 years ago and didn’t have it repaired. I saw a physio and took it steady for month or so then carried on as normal. I never noticed any subsequent weakness it that arm.