I would deffo let him go on loan to gain first team experience. I dont see Pep using him at all apart from maybe Swindon Town in FA cup for second half and maybe a league game as a sub when we are 5-0 up.
But even yesterday we were 5-3 up and he made 1 sub only with Palmer, Kayky, Mbete on bench. (Did Sterling, Mahrez, Bernardo really need to play full 90 minutes in this crazy run of fixtures...)
All he had is a short cameo vs Everton for 5 mins this season, coming on in 87th minute.
And an 18 minute sub app against Wycombe when we were already 4-1 up.
Thats all he had in terms of first team minutes, about 20-25 minutes and we are at half of the season.
We can have another Sancho type of situation if we are not clever here that someone else will develop him into a 50-100m player and profit from it.
Foden at same age before he turned 19 already had about 1000 minutes of first team football, starting coupe PL games, mostly subs of course, starting few Carabao, FA cup games, and even having some odd minutes in CL games.
He started Sahtar in 2017/2018 season in group stage then Basel in 1/16 round.
He was 17 only at the time of Sahtar game.
McAtee turned 19 on October and has a total of 25 minutes first team football. Surely if he and his agent compares this to Foden's trajectory then he is about 1.5-2 years behind and they will start wondering why.