The greatest tight end in the NFL believes LeBron James would have thrived as a pro football player ... 'cause Travis Kelce tells TMZ Sports the King would've been a serious "problem" in the league if he didn't become a basketball icon.
LBJ recently revealed he received offers to play for the Dallas Cowboys and Seattle Seahawks during the 2011 NBA lockout ... and said he would have likely tried out at tight end if he decided to play football.
Considering Kelce is a 5-time All-Pro tight end, a Super Bowl champ and a 6-time Pro Bowler, we had to ask about LBJ's chances in the league .