Baker played a key role in developing the teenager at Gresty Road and believes Wigan is an ideal move for him.
"He is going to play at a good level - and it is better to play in the Championship than at Under-21," Barker told the Manchester Evening News. "It was a big leap going to the Premier League, but United wanted to see how he was going to do. It would have been pointless to send him straight out on loan.
"They've had a good look at him and maybe felt he wasn't going to play regularly enough so have sent him to get some competitive football.
"I expect him to play at the highest level. He could play for England and I'd be surprised if he doesn't."
Barker added: "A lot of players have benefited from going out on loan, rather than playing reserve team football.
"He's going to get competitive games under his belt and make good progress at Wigan .
"It will be the right move for him. To ask a 19-year-old to play every week for United is a lot.
"To get 35 games at Wigan will do him the world of good."
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