Insult to Injury

I have been fighting a bum left knee on and off since highschool. There have been periods where it has kept me off the bike. Last week while working the market in NYC I somehow managed to inflame it once again. Three days of taking it easy and ice and Advil therapy helped, but now nearly a week later it is still not quite right. I've done two very easy hour long rides. The first wasn't good at all with burning pain above the kneecap. Yesterday wasn't so bad, but the ride was at the end of the workday and it cooled enough that I should have had knee warmers on. So I took it very easy again. Today I'll test it a bit further with some harder and longer efforts. There's a tt coming up this Sunday I'm signed up for, but I won't know till Friday whether I'll do it or not.