Rams Super Bowl champ Grant Wistrom ain't surprised the Rams fired Jeff Fisher ... 'cause it was time for the longtime head coach to go.

Wistrom -- who played for the Rams from '98-'03 -- says he's always respected Fisher as a coach, but knew the team needed to make a move given his 31-45-1 record and lack of success in L.A.

"It's a lot easier to change a coach than it is to change the players, and a change needed to be made, G.W. says, "obviously, they're not winning."

Wistrom also talks about Coach Fisher's public feud with Rams legend Eric Dickerson ... and whether that contributed to his firing.