Aaron Donald and Ndamukong Suh will be one of the most feared twosomes in the history of professional freakin' football ... former NFL star Willie McGinest tells TMZ Sports.
We saw McGinest -- a 3x Super Bowl Champ -- at LAX on Tuesday ... and asked him about the Rams' latest addition ... 5x Pro Bowler Ndamukong Suh.
"That's a scary combination."
Best ever?
"I can't go through history, but that's one of the best as far as interior defensive lineman playing together. That's definitely one of the most feared twosome you're gonna have," Willie told us.
Suh ain't the only stud joining L.A. -- who already had a good D -- as Aqib Talib and Marcus Peters also recently came over.
"They got a monster squad. It's gonna be exciting to see how it all comes together."
September can't come soon enough ...