Ole Gunnar Solskjaer has affirmed that any Manchester United transfer targets will not live a "comfortable" life at Old Trafford.
The Red Devils are understood to be in the market for a new centre-back and striker ahead of the summer window, with Jules Kounde, Raphael Varane and Erling Braut Haaland all being linked with moves to Old Trafford.
Man United could also reignite their pursuit of Jadon Sancho, but Solskjaer has warned any potential signings that they must be ready to cope with the physical demands of 45 to 50 games a season.
Speaking to the official Manchester United website, Solskjaer said: "If you want an easy, comfortable life then you don't play for Man Utd.
"You've got to be mentally strong and also physically strong and robust. To be successful you want to challenge yourself and these are the periods we want.
"I think if you manage to recover between [games] and you get your rhythm then that's the best way. If we are to end up successful this season, next season, in two years or in five years from now then you have to get used to playing 45-50 competitive games a season at least, that's what it should be for a Man Utd player and consistently.
"If you have five, six, seven players who can do that then we can challenge for trophies. I like to play games... we can drip feed and rotate of course."