Brandon Marshall Warns Cowboys To Not Dump Dak For Russ, 'Grass Isn't Always Greener'

Brandon Marshall says Jerry Jones would be crazy to dump Dak Prescott for Russell Wilson ... telling TMZ Sports straight-up, "The grass isn't always greener on the other side."

"Dallas, you have your guy," the former NFL star receiver says. "Pay him! Let the world know he is the guy!"

Dallas is one of only four teams Wilson's agent said the QB would accept a trade to ... and, because of the ongoing contract feud with Prescott, many have wondered if the 'Boys would consider a 1-for-1 QB swap.

Marshall -- who played with Wilson in 2018 -- says if he were running the team, though ... that trade would be a big no for him, explaining, "To me, you have your guy."

"Continue to build your team around [Dak]," Marshall said. "You know, the grass isn't always greener on the other side because you don't know Russ' style and how he operates and how he moves."

Instead of Dallas, Marshall says the much better fits for Russ are back in Seattle ... or with New Orleans or Las Vegas.

But, if Seattle does ultimately deal Wilson ... the 'Hawks will likely get a bunch of draft picks in return -- and Marshall could have some big-time insight into who would be good fits there.

Marshall's House of Athlete is putting on an NFL scouting combine later this week ... where Brandon will get an up-close look at how tons of top prospects test for scouts.