No knee pain while playing but only while squating and climbing down stairs..will quad strengthing help.

While playing what?: Sounds like patellar problem usually quad strengthening helps but avoid squats as they put too much pressure on that part of the joint.

It can: Sounds like you have a problem under your knee cap(patella). Most stress in this area during squats and going down stairs (chondromalacia pattelli) . The corner stone of pt for it is quad exercises : straight leg raising, "quad sets" (tensing muscle while knee straight/isometrically)and pain free arc exercises. Many online resources for exercises http://www.Youtube.Com/watch?V=xwc4flssv6e.