Shawne Merriman Says Chargers Should Avoid Hiring Bill Belichick, Jim Harbaugh

If Shawne Merriman was in Dean Spanos' shoes, he would NOT hire Bill Belichick or Jim Harbaugh to replace Brandon Staley ... telling TMZ Sports he thinks his former team needs to go younger with its next hire.

Of course, both coaching veterans have been rumored to be on the Bolts' radar following Staley's firing on Friday ... but Merriman made it clear, he would prefer it if L.A. looked elsewhere.

"The game has gotten much younger," the ex-Chargers pass rusher said. "If you look around, a lot of these head coaches are younger. They relate well to the players."

Belichick is 71 years old, while Harbaugh is 59 ... ages that Merriman obviously thinks just won't cut it when it comes to directing guys like 25-year-old Justin Herbert or 27-year-old Derwin James on the field.

But, don't get it twisted, he still loves both guys and their résumés -- he just said, "I don't know if that's the proper move in this situation."

"I really don't."

Merriman didn't have any names that he would rather hire -- though he did say he wants no part of being considered for the role ... as he's a bit preoccupied with his MMA promotion, Lights Out, which has a big event coming up on January 6.