Will the knee injuries ever stop?

After 2 weeks of nice temps I wake up to a dusting of snow. Hopefully tomorrow afternoon will be much warmer. First race of the year is at Fort Collins. I've been riding well since my knee surgery with little to no pain. That was until yesterday when I banged my right knee hard against a metal fixture at work. It's not swollen but it is tender to touch. I'll check it out today. So right now it's a game day decision.