Manchester United manager Louis van Gaal is at risk of a knockout punch as his side visit Stoke City in the weightiest fixture of the Premier League's jam-packed Saturday programme.

The 64-year-old Dutchman is reportedly one or two bad results away from the sack after a run of six winless games that has seen his team drop to fifth place in the Premier League and exit the Champions League.

Amid intense speculation that he is on the brink of being replaced by Jose Mourinho, Van Gaal stormed out of his pre-game press conference after just five minutes, wishing stunned reporters an ironic "merry Christmas".

In a subsequent interview with MUTV, he acknowledged that the trip to Stoke was a "must-win game".

"When you have lost three times in a row, then you need a victory. We have focused ourselves to do that, but it is not easy," he said.

"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."

Stoke's draughty Britannia Stadium is a forbidding place at the best of times and it has proved particularly hostile of late, with Chelsea and Manchester City among the visiting teams to have succumbed to Mark Hughes's side.

Hughes, a former United striker, expects Van Gaal to turn the situation around, but is unsentimental about the prospect of adding to the Dutchman's woes.

"They have got good players, they have got a good squad," said the Welshman, whose side have won only one of their last four league games.

Publicly, at least, Van Gaal retains the support of his players as he attempts to lift a side who have fallen nine points behind leaders Leicester ahead of the Boxing Day programme.

"It's not nice when you're getting criticised after every game," said captain and star striker Wayne Rooney.

"It's tough for the players to deal with. We get hurt because we're proud people and proud to play for Manchester United. When it's not going right, it's hard to take and frustrating."

Mourinho's sacking by Chelsea highlighted the dangers of managing in the English top flight and it is with interim manager Guus Hiddink in the dug-out that the champions will tackle high-flying Watford.

Reprising a role he previously performed in 2009 after the dismissal of Luiz Felipe Scolari, Hiddink has appealed to the personal pride of his players as he seeks to lift the London club from their lowly position of 15th place.

"They must have a heart full of the desire of an amateur," Hiddink said.

"If they don't have that desire then I will say: 'Thank you very much.' I don't need players who don't have the desire."

Hiddink watched from the stands last weekend as Chelsea turned in a vastly improved performance in a 3-1 win over Sunderland, but Watford, seventh in the table and chasing a fifth straight win, will be a different prospect.

Watford's recent success echoes that of Leicester, who continue to defy expectations ahead of their trip to Liverpool on Saturday.

Bottom of the table a year ago, Leicester have electrified English football this season and manager Claudio Ranieri is revelling in his team's new status as the neutral's darling.

Ranieri believes that their stamina will serve them well after comparing them to movie hero Forrest Gump following their dramatic 'great escape' last season.

"I am very confident because if Leicester last season saved themselves in the last two months, that means the stamina is fantastic," said Ranieri, whose side have lost just once in 17 games this season.

"Why can't we continue to run, run, run? We are like Forrest Gump -- Leicester is Forrest Gump."

Having established themselves as Leicester's number one challengers with an impressive 2-1 win at home to third-place Manchester City on Monday, Arsenal travel to mid-table Southampton.

Southampton are without a win in six games, but Arsenal manager Arsene Wenger has warned his team that the victory over City will soon be forgotten if they allow their level to drop at St Mary's.

"The confidence is very high," he said. "Confidence is built up very slowly and goes very quickly, so let's take care of our next performance."

City, six points below Leicester, hope to have captain Vincent Kompany available after a calf injury when they host second-bottom Sunderland.