The Argentine is expected to leave Old Trafford this summer following a fallout with boss Ruben Amorim near the end of the season.
Foster has doubled down on his criticism of Garnacho’s attitude, calling out the 20-year-old for his ‘haircut obsessions’ and urging the 20-time Premier League champions to sign ‘good and honest’ players instead.
“I think for Man United it's best to ship him out. If I was the manager, I'd be a little bit similar to Amorim in the case of I just want team players,” the former goalkeeper told talkSPORTS.
“I want a bunch of lads who are good, honest, hard-working team players. And I don't get that vibe from Garnacho, I don't get that vibe from a few of the players.
“You look at the full-time whistle after the Europa League game. You have Brennan Johnson doing an interview. He looks like he hasn't had a haircut for about three months, (hair) horrible all over the place, but his interview was incredible.
“You could tell he's a real nice lad, he's hard working, he does everything for the team. Then you look at Garnacho. Fresh trim a day ago, dyed blonde, ready for the final.
“The full-time whistle goes, he's sat on the pitch sulking by himself, not trying to get behind the other lads, picking them up, saying 'well done we got this far'. And I think that there is the big contrast. I just want good lads, honest, hard-working lads.”