More probably you just need to back off the effort a bit and give yourself time to rebuild your fitness. It won't take long. And while running is fine (I'm doing some of it myself) there's no reason why some long steady distance and tempo work on the bike shouldn't do the job just as well. Take it steady, do some resistance work (I suggest half-squats or leg presses, but no lifting post-surgery until the docs OK it) and you'll be back to your best in no time. Make it a medium-term plan to be in top shape for the start of next season.