Sanchez has struggled at Old Trafford since he left the Gunners in a swap deal in January 2018.
Overmars, who won the Premier League and FA Cup during a three-year stay at Highbury, says he has “great respect” for Sanchez, but believes he may have made a mistake by leaving the Gunners.
“I have great respect for Alexis because he did extremely well in Arsenal, I do not know if it was a good decision to leave.
“English football changes you, it turns you around, it took me a step forward. Arsene Wenger arrived a year before me, Dennis Bergkamp made a big impression in England, it was a fantastic time, I think we changed the history of the club a bit.
“This type of players were very important for Arsenal because that’s where they take you to focus, after Alexis, Arsenal tried to sign another player like that, but he was not given, so he could go back to Arsenal,” Overmars told ADN Deportes.