I don't think you'll risk growth but there is a disease called Osgood-Schlatter's (not serious but is painful and can stop you playing sport for a while) which causes pain and swelling around the knee joint.
It's very common in teenage boys who play a lot of sport, which is why taking proper advice and rest is critical.
However, you're doing the right thing in taking advice from a physio although the yoga and pilates can be very good for giving core strength, which is vital to a pace bowler. Do a little bit of research into it and I'm sure you'll find a good compromise.
Yes, a few of my mates got that Osgood-Schlatter's disease in their knees, I may be at greater risk since my knees are extremely weak. So weak that I cant squat for longer than 5 seconds without it hurting for about the same amount of time I was bending down afterwards.
Thanks for the tips, I will look into it and post when I find something.