We need to be very careful not to repeat the McTominay cycle with him. I'm not in favour of a relatively unproven academy player again becoming a starter due to being the best of a bunch of awful options. We have shown ourselves to be way too nice to move these players on quickly if needed, and we could just effectively have McTominay replacing himself in our team.
What we need to just do is buy a couple of top quality midfielders. Sell McTominay who has already proven himself not to be up to it, and then have Garner in the role Scott SHOULD have started off in as an understudy to some proper midfielders where he can slowly prove whether he is good enough or not. I am not in favour of just making Championship Nottingham Forest's midfielder a regular here, because that in itself is McTominay's standard. We would not ordinarily have signed a Forest CM who impressed in the Championship to immediately fix our midfield, and Garner shouldn't be asked to either. His role as a squad player is the right one. Scott's role as a regular has failed and he needs to be sold and replaced with a new regular, but Garner has not shown it should be him.
I can imagine he will be better than Scott, and I can see a scenario where being better than Scott excites a few people at first, and he becomes a regular. But soon Scott will be long gone, and we'll remember that being better than Scott was not actually where the real bar is, it is being good enough for United, but by then, Garner is an established regular and we basically have Scott all over again for a few years.
Farewell Jimmy