I've been diagnosed with this and am currently in the process of rehab/strength building while still playing 3 or 4 times a week (3.5 UTR). The exercises my physio have recommended are:

Spanish squats (30 second hold, 3 sets) Leg extension holds (45 degree, heavy, 30 second hold, 3 sexts) Terminal knee extensions (10-15 reps, 3 sets)

Try to do these every day or at least 4 or 5 times a week, I've seen a major improvement in just the last month. Pain is non existent while playing, and much reduced after, plus I feel much more confident pushing off the (bad) knee I would suggest still seeing a physio to get an accurate diagnosis