Don't get Odell Beckham Jr.'s ring size just yet ... so says Nate Burleson, who tells TMZ Sports he loves the Rams' newest addition -- but there's still one thing standing between them and a Super Bowl.
Of course, Odell is now in L.A. after a disastrous stint with the Cleveland Browns ... and could play a big role in the Rams' offense with Robert Woods going down with an ACL injury.
Burleson gives a message to OBJ as he prepares to suit up for his new squad ... telling him to be himself and ball out.
"Block out the noise, like I always say," Burleson says. "Make your next act your best act."
Nate thinks the Rams are a legitimate Super Bowl contender ... but says the OBJ signing doesn't make it a foregone conclusion they'll win it all this season.
"But we can't give 'em a Super Bowl ring just yet, they gotta go earn it," he says.
"And they gotta go through Thanos -- I mean Tom Brady."
Burleson also points out the new off-field opportunities OBJ has in L.A. ... imploring Beckham to wait until after he finishes playing football to pursue a fashion, music or acting career.
"Wait till your career is over, O," he said. "Then you can drop an album, get into movies, do all that stuff."