It's probably more likely that they took a player that had just come back from injury to the World Cup, instead of putting him through a tailored training regime to get him back to full match fitness he just did the same tactical training and match practices as the other England players.
Southgate was only ever going to use him as a substitute so all he had to worry about was him being up to speed with the tactical plan of the team and that he could play for 20 to 30 minutes at a time. Southgate and the England staff have no interest in making sure players are fit and ready to play a full league season, their only remit is the tournament they're managing these players in, not the competitions their parent clubs are involved in.
Pep then used a phrase in his conference that a native English speaker may not have done (isn't the first time) then the press make a huge thing of it because there's no football on and they've got a 24 hour sports news channel to fill/papers to sell/clicks to gain and the only other football news is related to Liverpool fans misbehaving yet again. Can't have negative headlines and stories about Liverpool so suddenly every easily manipulated football follower is up in arms because Phillips is suddenly an unprofessional fat bastard.