Kids playing more than one sport at a time??? Is it detrimental to academic as well as social development?

I am the mother of a 13 year old son who is gifted in athletics as well as academics. My question is ,how many sporting activities with overlapping practices should be allowed at any one given time? His team just finished up with youth football December 8,he went directly from football to basketball practices without let up,he is practicing 4x a week,playing 1 to 3 games a week for his middle school(actually he is just a fair basketball player), but a state placer in wrestling many times over as well as the MVP and Offensive Player Of The Year in football,but now that our City Youth Wrestling Program has started he is receiving calls from his wrestling coaches who are kind of "pushing" him to wrestle for them (he has wrestled with them for years but decided to try basketball instead this year and forgo wrestling til High School,does anyone think it is realistic that this kid would be able to maintain this rigorous schedule and still maintain a 3.8 G.P.A? Tournaments are on Sundays!