Louis van Gaal
Louis van Gaal's Manchester United are without a win in six matches Getty

Manchester United boss Louis van Gaal has urged his players to raise their game during the hectic festive period to help salvage their season. Writing in the match programme for United's home game against Chelsea on 28 December, Van Gaal said he is experiencing the worst period of his Old Trafford career.

"There's no disguising the fact we're in a very bad period. Things must begin to improve immediately," Van Gaal is reported as writing by the BBC.

In a separate interview with MUTV, the Dutchman described the Boxing Day clash with Stoke City at the Britannia Stadium as a must-win game. United are on a six-match winless run in all competitions and were booed off the pitch at Old Trafford following a 2-1 defeat against Norwich City on 19 December.

The Red Devils are also out of the Champions League and were eliminated from the League Cup by Championship side Middlesbrough in October.

'Must-win game'

"Yes, I think so [it's a must-win game] because, when you have lost three times in a row, then you need a victory," Van Gaal told MUTV in an interview that aired on Christmas Eve.

"We have focused ourselves to do that but it is not easy. Stoke City have won against Manchester City, for example, and it's a special ground. It is not easy with a lot of circumstances that are not suitable always to playing good football."

Juan Mata-Michael Carrick
Juan Mata (left) and Michael Carrick could both start for United against Stoke City Getty

The former Barcelona and Bayern Munich boss insisted that United's season can be turned around, but said the players will have to step up.

"One month ago, we were first in the Premier League. Everything has changed but it's also possible to be, next month again, in the fighting position for a title. But we have to win first against Stoke City, that is the main focus," he said.

United currently sit outside the top four of the Premier League by virtue of goal difference and are nine points behind leaders Leicester City.