But it is easy to snag some pick up games too. There are some guys at WP that you could always ask if they want to throw down some time at singles. I have seen some guys that I would have asked for their contact info had I still been playing singles.
My body will not allow me to play singles much anymore. Shoot, I only play once per 4 months on average. I played 3 times this year and that is more than any year previous in the last 5. I imagine singles will only get worse for me and my body over time. But that is just me, you are not rolling with 7 injuries at all times.
You can play singles if you just get your body back used to playing it some. I find it hard to believe that your body is so bad off that you can't play singles anymore with any regularity? If that is the case then it is time for the replacements.............hip, shoulder, knee.

While you're at it, you might as well just order an upgrade...........Scott 2009! The new and improved Scott that doesn't have 7 injuries.
I am a firm believer in getting your body familiar with what you are asking it to do physically and then you can expect it to be able to handle what you are doing. Don't play singles all year and then play 6 straight days of singles and expect the body to break down. Ease into singles by playing 1 time per week and then over the next few weeks maybe upping it to singles 2 times or more per week and then your body will be able to hang.
I also like to try to think of injuries as serious (not going to be able to continue playing or going to make it worseby continuing) and not serious or more like nagging injuries (pains, mental crutches.......stuff that just needs a little rest or to be played through).