Aaron Donald doesn't seem convinced Rob Gronkowski's played his last game in the NFL ... 'cause the Rams superstar tells TMZ Sports, "He's retired for now ..."
Of course, the topic has been a huge talking point in NFL circles after the future Hall of Famer abruptly announced he's callin' it a career at just 29 years old.
Count Donald in as one of those who needs to see it to believe it ... but if it is, in fact, true, AD has HUGE respect for the Patriots legend's game, regardless.