The Red Devils have enjoyed an impressive start to the new campaign and sit joint-top of the Premier League alongside near neighbours Manchester City after collecting 13 points from their first five games.
United have also made a comeback in the Champions League and comfortably won their opening group stage encounter with Basel 3-0.
Mourinho’s men are competing on four fronts once again and that involves taking part in the League Cup, rebranded the Carabao Cup this season.
In order to keep his side fresh, the Portuguese gaffer has confirmed David De Gea, Eric Bailly, Nemanja Matic and Antonio Valencia will sit out United’s showdown with Championship outfit Burton.
Mourinho explained: "I gave two days off only to four players. Apart from that, everybody is selected.
"Do you want to know which four? De Gea, Valencia, Matic and Bailly."
Mourinho confirmed he’s taking the Carabao Cup seriously though, adding: "Oh, yes. Serious. Because it's football, it's competition. We take it seriously.
"Of course, we're not playing David or Bailly but, if we go to the next round, probably these guys will play and I will give a rest to others. Our squad is good.
"We don't have 30 players, we have what we have, and a couple of injuries right now with Paul Pogba and Axel Tuanzebe. So we need some of the players that played on Sunday to play and we need some to be on the bench.
"We need to be with a strong team. I know the quality of the Championship and I know, if we don't take the game seriously, we are going to lose."
United are back in league action when they travel to Southampton on Saturday.
