The new England cap's contract with LOSC expires in June.
He told The Times: " I sometimes think about where I would be now (if I had stayed at United). I think it's normal to feel that way, but the jump and the path that I took, the places I've been, what I've learned from the different coaches along the way, the details, the effort and the love they put into my game… I think not that I would be where I am now (England international) without that."
Gomes trained with Manchester United's U18 team even before he had turned 15.
"At that point, there was nothing that worried me. I loved getting into it. I really thought I was ready to play with them.
"I don't know if it was delusional, but my height never affected me. It wasn't until I got older and comments were thrown around more, things like, 'If you want to be a pro, you've got to be able to do this in the gym', that instead of trying to show my strengths, I'd go out and try to crush people to show that my size didn't matter. It took me a while, but you learned to get over it."
The midfielder is not closing the door on a return to United.
"As fantastic as it would be, after finding happiness abroad, I know that (playing in the Premier League) is not A and O.
"There will always be that sentimental soft spot, so of course it would be difficult to say no (to Manchester United)."