That is according to The Times columnist Tony Cascarino.

Shaw made his first league start of the season in the 1-0 win over Bournemouth last week and was praised for his performance by manager Jose Mourinho.

But just when the 22-year-old may have hoped to have made a breakthrough, he was left on the bench in yesterday’s 2-1 win over West Brom.

Shaw could return to the United starting line-up on Wednesday when United take on Bristol City with Mourinho likely to shuffle his team ahead of the busy festive period.

But Cascarino believes Shaw must leave to revive his career.

Cascarino told The Times: “Luke Shaw remained on the bench yesterday and watched a winger - Ashley Young - and then a centre back - Marcos Rojo - play in his position.

“He needs to leave Manchester United and restore his reputation as a top-flight left back.

“A footballer’s career is not long and he can’t waste his talent sitting on the bench - even if he will earn more money doing so.”

Speaking after Shaw’s display against Bournemouth, Mourinho said the England international was an option for him.

“I’m not saying first or second choice, he’s an option,” Mourinho told Match of the Day.

“His history is an incredible injury and more surgery at the end of last season. 

“He needs competitive matches, we gave him that and he had some cramps so we had to change him. The standing ovation for him I liked, it helps the player.”