Ander Herrera and Michael Carrick are struggling to force their way into the Manchester United starting XI because Marouane Fellaini and Nemanja Matic are in the form of their lives, according to Jose Mourinho.

Carrick was named club captain this summer after signing a one-year contract extension but has not seen a minute of first-team football this season, making the bench four times after not even being included in the match day squad for the first three Premier League games of the season.

Herrera, who grew into an integral member of the starting 11 under Mourinho season, has also struggled for game time, having made just one start appearance from five in the league having also been left out of the match day squad for the Champions League opener against Basel.

In that 3-0 win over the Swiss champions, United lost Paul Pogba to a hamstring injury with Fellaini coming onto replace him, scoring the game's opening goal with an impressive performance earning him a starting role alongside the ever-present Matic against Everton.

The Serbia international will be given the night off on when United welcome Burton to Old Trafford for their Carabao Cup third-round clash. That could present 36-year-old Carrick with his first start of the season, with Mourinho expected to rest two players he believes are playing the best football of their careers.

"We gave Michael Carrick a contract because we think he's a good player and an important player," Mourinho said. "He's just in a team where I think, in this moment, Matic and Fellaini are in the best form that I have ever seen them. I never saw Matic playing so well. I never saw Fellaini playing so well."

Pogba's injury is expected to rule him out until the next international break in October at the earliest with Carrick and Herrera now in line to get more opportunities.

"He [Carrick] is in a team with these two guys, playing absolutely phenomenal," the United boss continued. "For Carrick and for Ander, it's just patience because their time will arrive. They are going to be important players for us, for sure. That's the team, that's the squad. We cannot play with [only] 11 guys."

Fellaini and Matic
The formidable duo have been heavily praised by the United boss. Getty