Jose Mourinho said it hurt him to have to leave players out of his side after Manchester United swept aside West Ham United 4-1 to reach the semi-finals of the League Cup on Wednesday.
Zlatan Ibrahimovic and French forward Anthony Martial both scored twice at Old Trafford to take the four-times League Cup winners into a last four meeting with Hull City.
Mourinho handed Martial a start along with Armenian Henrikh Mkhitaryan and even brought out-of-favour midfielder Bastian Schweinsteiger on as a late substitute.
Martial had missed out on the Premier League draw against West Ham last weekend and Mourinho said rotating his squad gave him no pleasure.
"It hurts me, it hurts me," he told the club website (www.manutd.com).
"It hurts me a lot to leave (Memphis) Depay and Ashley Young at home. It hurts me a lot like last week when I had to leave out Martial, and next week I'll leave another one.
"We have so many players for these positions and it's good for me but it's bad for them ... I cannot give to everyone at the same time, so it hurts me."
Midfelder Mkhitaryan, who has featured in only 10 games this season, was in the thick of things, supplying a backheeled assist for Ibrahimovic's early opener and a well-judged cut back set Martial up for his first goal.
"We know the reason we bought him and were waiting for his reputation. It looks like it's coming," Mourinho added.
West Ham manager Slaven Bilic rued his side's slow start to the match.
"We can't have a slow start against them because they are very good when they are one up. They have those kind of players," he told the club website. (www.whufc.com)
United will take on Hull over two legs in the semi-finals on 10 or 11 January and 24 or 25 January to decide who plays Liverpool or Southampton in the final.