The ex-Bama star was a 7th round pick in the 2018 NFL Draft -- and knows he ain't taking Zeke's starting job.

Instead, he wants to be the best #2 back in the league -- and hopes Zeke's down to help him get that spot.

"Man, I just hope Zeke ... help your boy out," Scarbrough told TMZ Sports.

"We coming in, work together. We trying to win, we trying to be the best duo that ever came through in NFL history."

Scarbrough has all the tools to be a stud in the league -- he's 6'1", 228 lbs and ran a blazing 4.52 in the 40-yard dash at the combine, the 6th fastest time for a running back.

And get this ... Scarbrough spotted Terrell Owens at LAX, and it turns out they already know each other because Bo was just working out with T.O. and Julio Jones just a few days ago!

In fact, Owens even dished out some advice for Scarbrough on how to make it in the NFL.

That's Hall of Fame advice, Bo ... better listen up!