Tennis Shoulder

So after playing tennis while my parents were here, which was the first time in almost a year that we played the Wii, we realized we've been missing out. So Dave has been playing tennis a few nights this week, and I joined him last night. We played against each other, which is always fun, but it doesn't improve your individual skill level if you're playing against someone. But once you play against the computer when you win you can increase your skill level. So while Dave and I played against each other, I held my own pretty well. But not too long after we started playing my right shoulder started hurting. This had happened to me last year, when we'd play all the time, and I called it my tennis shoulder. So last night my tennis shoulder started acting up again. We played maybe 3 or 4 best out of 5 series, but then I played against the computer. And the sad thing was, my skill level was about 560, and I was playing against a pair that had around 80 and 110 skill level, and they beat me. How does that happen? My skill level went down, I'm embarrassed to say (but apparently not too embarrassed to blog about). And to top it all off, all day my right shoulder has been hurting. I'm watching Dave play right now, and it's like watching a real tennis match on TV. He's really good, up in the high 900 skill level so he plays for a long time in a best out of 5 series and he just keeps getting better. I had to play a few more times against the computer to redeem my skill level and break 590 finally. I don't think I'll ever go pro, but maybe if I ice my shoulder or really stretch it ahead of time. Wow I sound like a Giik.