Kevin,
Icing is an anti-inflammatory precautionary measure. Just the same way pitchers run after a start to try and reduce lactic acid buildup, position players are not at the same risk.
If you had some soreness or stiffness in your knees the day after catching, then icing may be the first step of a preventative maintainance plan. If that didn't work, an NSAID type anti-inflammatory would probably be the next logical step. Although Ibuprofen, Tylenol and Aspirin have long been staples of pain and anti inflammatory management, more people these days seem to be getting better results with Naproxen (Aleve).
I personally know pitchers that are on daily maintenance programs of 1000 mg. per day (500 mg. twice daily), throughout the pitching season. I know one pitcher that ran out of Naproxen, and two weeks later could barely pitch and looked awful (this after being dominant most of the season). Right after that, he resumed his daily Naproxen and within 10 days, was back to his dominant form with total range of motion restored.
Without any day after symptoms of inflammation, my personal opinion, (I'm not really a doctor, I just play one on the internet
), would be that icing, or medication, is unnecessary.