MANCHESTER -- Jose Mourinho has confirmed Ander Herrera was left out of Manchester United's Champions League opener for tactical reasons, although the midfielder is set to return to the squad this weekend with Paul Pogba an injury doubt.
Herrera was not in Mourinho's 18-man squad for the 3-0 win over Basel at Old Trafford on Tuesday with the United manager revealing afterwards he was not carrying an injury.
Mourinho opted instead to pick Pogba and Nemanja Matic with Marouane Fellaini and Michael Carrick on the bench, leaving no room for the club's reigning player of the year.
Herrera, who started the 2-2 with Stoke on Saturday, could return against Everton on Sunday with Pogba likely to be ruled out with a hamstring injury.
The France international is set to have a scan on Wednesday to determine the severity of the injury he picked up in the first half against the Swiss champions.
"No reasons to be out," Mourinho said of Herrera at a news conference on Tuesday. "We are playing only with two midfield players, with Matic and Pogba, which are playing really well and without reason to change.
"The only match that we decide to play with three [against Stoke] he played.
"Today we went back to two again and I had on the bench Carrick and Fellaini, which were also important players in the last season.
"We have a group of players and the players must be ready to play and not to play.
"Ashley Young was not on the bench in the last match and today he started the match and he played for 90 minutes, and the next match you can have another surprise of some player that you think is going to play and is not going to play.
"It's the squad we have, I have to use the players and that's the life in clubs with squads of quality."
United's strength in depth meant Mourinho was able to compensate for the suspensions of Eric Bailly and Phil Jones against Basel by handing starts to Chris Smalling and new £31 million defender Victor Lindelof.
Bailly and Jones are set to be reunited against Everton with Lindelof and Smalling returning for the League Cup against Burton Albion on Wednesday.
Mourinho said: "[Smalling and Lindelof] train really hard. They train together always in the same team because I knew that they had to play this match together.
"If you want to anticipate the next weekend [against Everton], I probably play Bailly and Jones because today they didn't play, because they are fresh, because it makes sense for them to play again, but then two days after we have a League Cup match [against Burton] so Victor and Smalling again.
"So we need this and in the Premier League and the Champions League I have to choose the players in relation to the quality.
"When I know that in the Premier League I'm going to face one of these defensive walls, probably Victor is the best to come with the ball, to attack spaces in midfield, to find people in between the lines.
"So what I want is to have the players available and sometimes they are not playing, but for me as a manager it's important to have options."