Luke Shaw
Luke Shaw is not fit enough to start against Liverpool at Anfield Getty Images

Manchester United defenders Luke Shaw and Marcos Rojo are not fit enough to start against Liverpool on 22 March, according to manager Louis van Gaal.

However, the duo, who completed moves to Old Trafford in summer 2014 from Southampton and Sporting Lisbon respectively, could feature among the substitutes at Anfield as United seek to retain their grip on fourth place heading into the final weeks of a frenetic 2014-15 campaign.

Rojo missed the comfortable 3-0 victory over Tottenham on 15 March with a groin problem, while Shaw was also ruled out of that match after being replaced by Phil Jones at half-time of the FA Cup quarter-final against Arsenal.

"Louis van Gaal tells #MUTV that Marcos Rojo and Luke Shaw are not fit enough to start for #mufc at Anfield but may be on the bench," the club tweeted prior to Van Gaal's official press conference.

Twitter/@ManUtd

Speaking to the press ahead of the trip to Merseyside, Van Gaal also provided an update on the fitness of compatriot Robin van Persie.

The former Arsenal striker has missed four consecutive games with an ankle injury sustained during the defeat to Swansea City in February but is said to be starting to run again as he steps up his bid to return before the end of the season.

"I want to win against them again. It's very important," Van Gaal said ahead of the match against Manchester United's traditional rivals and main competitors for Champions League qualification. "I think every player knows the importance of this game. We are in a very crucial stage and cannot lose."

United supporters will be boosted ahead of the clash with the news that Michael Carrick has signed a one-year contract extension with the club following his excellent performance against former employers Tottenham.

The 33-year-old's previous deal was due to expire in June but he has now prolonged his stay until at least the summer of 2016.