Rashford is currently on loan at Spanish giants Barcelona, who have an option to sign him permanently in the summer.
The English star has thrived away from home, scoring ten goals and bagging 13 assists in 34 appearances for Barca across all competitions this season.
Reports have linked the 28 year old with a move back to United after proving his worth in La Liga but speaking to CasinoHawks, Saha believes this may be a mistake for the club who should move on.
“It's a difficult one. I love Rashford, I love his quality. I'm not surprised that he's doing well at Barcelona. He can't rewrite what happened before, and this is the best version of him we’re seeing now.
“I think sometimes you need to move on. If he comes back it wouldn’t completely erase everything that happened, there are bad memories there and that's not something he's dealing with at Barcelona.
“I think it would be strange. I think sometimes you need to move on. A lot has been said and it seems to be the best place for him, Barcelona.
“Yes, he's a talented player, and maybe his return can be considered. But even as a big fan of his, I’m not sure it would help the club.”
Rashford was frozen out at Old Trafford under former boss Ruben Amorim but could find his way back under Michael Carrick or a permanent manager once the season is over.