Jose Mourinho says Luke Shaw "has to improve" if he is to get back into the Manchester United starting XI after the defender made his first appearance since April during their Carabao Cup win over Burton Albion on Wednesday (20 September).

The left-back has struggled with form and fitness in the last two seasons making just 16 appearances in the Premier League. Shaw has struggled to break into the team despite being fit, with the manager preferring Daley Blind, Matteo Darmian or even winger Ashley Cole at the left full back position.

The Portuguese manager was harsh in his criticism of the player when he was fit last season, going to the extent of questioning Shaw's understanding of the game despite an impressive cameo off the bench during their draw against Everton.

The 25-year-old will not be part of the United squad that travels to St Mary's to take on Southampton on Saturday (23 September) and Mourinho is not expecting him to be back up to speed immediately. He admits that Shaw will have to go through the process and prove his match fitness.

The United boss also referenced other managers, in particular Arsene Wenger, who has started Alexis Sanchez just once in the Premier League this season. The Chilean has been used for Arsenal's clashes in the Europa League and the Carabao Cup.

The French coach made it clear that he was not making a statement with his wantaway winger, but that Sanchez lacked match fitness to play from the start in the league. The Chilean is expected to start when the Gunners take on West Bromwich Albion on Monday (25 September).

"He has to work. You [media] saw the [Burton] game, you saw the same as I see, and so are you asking if he plays tomorrow? No, he is not playing tomorrow. He has to work. He has to improve," Mourinho said, as quoted on Sky Sports.

"Look, he doesn't play for six months. I am not expecting him to arrive on Wednesday and to be man of the match or to be running up and down for 45 minutes.

"It's just a process. He doesn't play for a long, long time. You have other players in the Premier League that in this moment who are not starting matches and their managers just say 'they're not in the best conditions'. And we're speaking about some of the best players of the Premier League," the Portuguese coach explained.

Luke Shaw
Shaw is not close to making a return to the starting XI despite returning to full fitness Getty Images

"I heard last week the Chelsea manager saying that, I heard Arsenal manager said that. The players are not in their ideas, in their analysis, they're not in the best form after important injuries and long time without playing.

"Luke had surgery and a long time without playing football. I cannot expect him to be back and to be strong, strong, strong in his work," he added.