Marcellus Wiley is all for Jimmy Garoppolo dating porn stars ... and he doesn't care if the QB's marketability takes a hit -- telling TMZ Sports, "I think he's made enough money, he doesn't need every damn endorsement!"
We got the ex-NFL star out at Equinox and he told us, because of Jimmy G's new $137.5 MILLION contract ... he can afford to do things like take the star of "Bra Busters 4" on a VERY public date.
"He made $137 million off of seven games, do you need Pepsi too?