Blake Shelton: Hey Dallas Cowboys, CALL TIM TEBOW!!!

With the Dallas Cowboys thin at QB ... Blake Shelton has some advice for Jerry Jones -- CALL TIM TEBOW!!!!

We got the country superstar and avid football fan out in NYC Thursday and asked which QB America's Team should sign to back up Tony Romo now that his backup, Kellen Moore, has a broken leg.

Shelton's been campaigning for Tebow for a while -- claiming the guy deserves to be in the NFL more than other QBs ... especially since he WON a playoff game!