If Brandon Jacobs were in charge of the Pro Football Hall of Fame, Eli Manning wouldn't have to wait long to have a bust in it ... as the ex-Giants tailback says his former teammate is "no question" a first-ballot Hall of Famer.

Jacobs didn't mince a single word when TMZ Sports got him talking about Manning's HOF candidacy this week ... saying Eli's two Super Bowl wins over the New England Patriots should be enough for a gold jacket alone.

"Well, s***," Jacobs said, "he beat Tom Brady twice -- that's enough!"

Jacobs, though, says Manning's got the stats to get in as well ... explaining the former New York quarterback's numbers "are up there with just about all the guys that we consider great."

Plus, according to Jacobs, Manning's teams were never really that good ... but he still somehow ended his 16-year NFL career with two championship rings on his fingers.

"I think Eli is by far first-ballot Hall of Fame," Jacobs said, "and he definitely deserves to get in this year."

Eli was just named one of 15 modern-era finalists for the Class of 2025 -- vying for coveted spots alongside names like Luke Kuechly, Jared Allen and Steve Smith Sr.

He'll find out Feb. 6 if he'll get the call in '25 -- but Jacobs seems to think it's already a foregone conclusion.

"No question," he said.