Rob Gronkowski could be catching passes from Tom Brady in a REAL game this season ... so says Jay Glazer, who tells TMZ Sports he thinks the TE could definitely unretire this year!!!

"Could he possibly come out of retirement for a last little playoff push? Why not?!" Glazer says ... "Why wouldn't he?!"

Of course, Gronk is currently enjoying the retired life ... he's been partying up with his swimsuit model GF, Camille Kostek, and traveling all over the world dancing his face off.