Chelsea and Manchester united are in the same exact condition. The blues performance is purely mediocre and having these players, playing like novice.
I think Chelsea and Manchester united problems are separate issues. For Chelsea; they have a new disjointed team of promising players with little experience, and few quality players in the team; this leads to conflicting performances in the team. For Manchester United; it is more of a tactical problem than injuries; Ten Hag is getting exposed tactically; and deserves the blame; he can only deflect the pressure for a while.
Whoever is responsible for transfer decisions and squad engineering needs to say goodbye. If United spend 200 million euros and they should get one of the likes of haaland, bellingham, mbappe and kane instead of mount, onana and hojlund. Or do not miss out on Cancelo or get the boys from Napoli at least. The club's internal technical team can neither bring in players from the youth system, nor develop existing players, nor adapt newcomers quickly.