Ole Gunnar Solskjaer says playing for Manchester United has always been "survival of the fittest" – but accepts that his high-intensity approach could be behind some of the 10 injuries they are facing at Crystal Palace.
Jose Mourinho's temporary replacement has brought a swift change in approach and fortunes, with the Old Trafford giants still unbeaten in the Premier League under the Norwegian ahead of Wednesday's game.
The intense 0-0 draw against rivals Liverpool was the latest impressive performance overseen by Solskjaer, who had to deal with Ander Herrera, Juan Mata and his replacement Jesse Lingard being forced off through injury in the first half.
All three will miss the trip to Palace and their withdrawal meant Marcus Rashford had to play through the pain, having sustained an ankle injury that needs assessing ahead of facing Palace. There could be as many as 10 missing for United.
Anthony Martial, Nemanja Matic and Phil Jones have been ruled out, so too Antonio Valencia, Matteo Darmian and Mason Greenwood.
Asked if the increased running he demands has brought on the muscle injuries, Solskjaer said: "It's probably linked, yes, because when do you make that change?
"Do you wait until pre-season and think you will change results by just not asking them to run?
"Or do we start now and show them what the demands of intensity, on how we want to play?
"Of course, you have seen what I have chosen. I have chosen we need to play as a Man United team and if you want to be a part of Man United, it's a survival of the fittest isn't it?"
Solskjaer says there has not really been time to work on fitness thanks to a frantic schedule, while muscle injuries sustained by the likes of Mata, Matic and Herrera are just part of players "getting older".
But such absences bring chances to others, meaning academy graduates Tahith Chong, James Garner and Angel Gomes will be part of the squad in London.
There are also opportunities for more experienced players with Romelu Lukaku among those looking for a breakout performance under Solskjaer, who turned 46 on Tuesday.
The Belgium international has admitted to bulking up for last summer's World Cup and Solskjaer was asked whether the striker needed to shed a little more given the way the United boss wants to play.
"You know I can understand why when you go to a World Cup and you see the teams that you play, it might be that his physicality took over that part of preparation," the United caretaker boss said.
"And for me, we ask our forwards, strikers, to work at higher intensity, runs in behind, but that's what Rom likes, so I'm sure he'll be fine.
"Muscle is not so difficult to get rid of and he's lean, but he's muscly."
Alexis Sanchez, Andreas Pereira and Scott McTominay are others that will look to push their case for injury-hit United, as will high-profile summer signing Fred – a player that has yet to justify his lofty price tag.
"Play well when he gets a chance, keep on training as he does, keep working," Solskjaer said when asked what the Brazil international needs to do.
"We've had a midfield three of Herrera, (Paul) Pogba and Matic – they've done really well together.
"It's not like we've been really bogged down with too many games. That's why we've kept them three together.
"McTominay was the obvious choice against Liverpool because he's an academy kid. We had five academy kids on the pitch at one point. He knows what it means.
"Fred will get his chances – maybe tomorrow. You look more to the time it needs sometimes to settle. You see Juan Sebastian Veron, he's one of the best I played with and it took him time to settle in England.
"I'm sure Fred will, when given the chance and a run in the team, grab the opportunity."
