Mark Cuban: HGH Should Be Legalized In Pro Sports ... If It Works

Mavericks owner Mark Cuban says he's all about HGH usage in professional sports ... if it can be proven it helps athletes recover from career threatening injuries.

Mark called in to "TMZ Sports" on FS1 to talk about Peyton Manning's HGH scandal and when asked if he thinks the controversial drug has any place in pro sports ... the Shark sounded off.

Check out the clip -- Cuban ... who has donated money to determine the effectiveness of HGH ... believes strongly that if it works ... it shouldn't be banned.