Manchester United boss Erik ten Hag admits he's having to manage Rasmus Hojlund through games.
The Dane is carry a back strain.
After substituting him for victory at Sheffield United, Ten Hag said: "You see he plays often whole games but behind us we have to manage his game minutes.
"Coming up are many games. So we are now in October but until the end of the season there are so many games and we need everyone on board, we need everyone sharp and to keep them sharp.
"If I saw the programme for the coming weeks, we have to swap during games, between games, otherwise we don't keep the energy, we don't keep the focus in the team and we don't get them so fresh for every game.
"Also, we want to do something with subs to bring a new energy into the team and from a tactical approach we want to do something."