Listen up, rookies ... ex-NFL star Andre Rison is shelling out some VERY valuable advice on how to NOT go broke like he did ... telling TMZ Sports what he wishes he'd done during his playing days.
FYI -- the former 1st-round pick made more than $20 MILLION during his 11-year career -- but ended up filing for bankruptcy in 2007 after years of spending his earnings on jewelry and partying.
Rison says it's a "drastic change" for these young players to become rich basically overnight ... and says focusing on your closest family and friends is important, but it should end there.
"Remain loyal to the people that helped you get to that point, no doubt ... but you don't owe anything to anybody, really," Rison says.
Rison says rookies gotta handle their business on AND off the field ... which means getting in touch with the right representation and people who know how to handle that much money.
There's more ... we also talked to Rison about whether Dez Bryant can be an elite receiver ... and you're gonna want to check out his answer.