Manchester United's squad has been stretched to the breaking point by the demands placed on the club by an extended run in Europe's second-tier club competition, according to manager Jose Mourinho.
United, who are destined to finish outside the top four in the Premier League this season, have reached the final of the Europa League, where beating Ajax Amsterdam on May 24 will grant them qualification for next season's Champions League.
Mourinho said he would try to rest players for United's last two Premier League games starting with Wednesday's trip to Southampton - but added that the current fixture congestion was something he had never experienced before as a manager.
"The accumulation of the games, I never had that," Mourinho told a news conference on Tuesday.
"You know that in all of my career I was never out of European competitions in the group phases. And in the last 16 I was out only once. So I reached the semi-finals 10 times. I go always until the end of the competitions.
"I normally have a lot of matches, but like this I never have, I never have ... This is crazy."
United won the League Cup earlier in the season and reached the quarter-finals of the FA Cup, while a host of injuries -- like the one that ended top-scorer Zlatan Ibrahimovic's season -- has further reduced Mourinho's options.
The Portuguese, who confirmed that midfielder Paul Pogba will miss Wednesday's game following the death of his father, said he was struggling to grant his players time off to recover between matches.
"I am giving one-day holiday 'a la carte', if you understand," Mourinho added. "(Daley) Blind one day off, (Henrikh) Mkhitaryan one day off, (Ander) Herrera one day off.
"What I want for the players is a good attitude, is a positive attitude, a positive approach, is team spirit, is understanding that some guys, they have to sacrifice themselves for the good of others."
United host Crystal Palace in their last league game of the season on Sunday, before taking on Ajax in the Europa League final the following Wednesday.
(Reporting by Simon Jennings in England, editing by Larry King)