Louis van Gaal is facing the sack at Manchester United if the club lose to Stoke City or Chelsea during the festive fixture period.

With United suffering a third successive defeat against Norwich City at Old Trafford on Saturday, Van Gaal is under mounting pressure, with the club hierarchy aware of growing discontent within the playing squad and increasing frustrations among the supporters, a minority of whom chanted the name of Jose Mourinho during the 2-1 loss to Alex Neil’s team.

Despite Van Gaal claiming after the Norwich defeat that he retains the backing of his players, the Independent is aware of senior figures within the dressing room who have grown tired of the Dutchman’s approach, both in terms of tactics and a perceived obsession with critical post-match analysis in “evaluation” sessions overseen by performance analyst, Max Reckers.

While United’s owners, the Glazer family, and executive vice-chairman, Ed Woodward, had retained faith in Van Gaal, who arrived as successor to the sacked David Moyes in July 2014, the club’s Champions League elimination earlier this month, quickly followed by Premier League defeats against promoted clubs Bournemouth and Norwich, have left the 64-year-old fighting to save his job. It is understood that a further defeat at either Stoke on Boxing Day or against Chelsea at Old Trafford next Monday will signal the end for the former Ajax, Barcelona and Bayern Munich coach at the midway stage of his three-year contract as United manager.

Carlo Ancelotti’s appointment as Bayern Munich manager, announced at the same time as confirmation of Pep Guardiola’s departure from the Allianz Arena at the end of this season, has left United without their favoured replacement for Van Gaal.

But Mourinho’s dismissal as Chelsea manager last week and Guardiola’s availability, despite strong indications that the Spaniard will move to Manchester City next summer, have given the Glazers two proven options to pursue as long-term successors should Van Gaal be sacked.

Manchester United vs Norwich player ratings Show all 22 1 /22 Manchester United vs Norwich player ratings Manchester United vs Norwich player ratings <b>Manchester United:</b> David De Gea - 5 out of 10 Should have done better when faced with Jerome as he went down too early to allow the striker to lift the ball over his head. Left stranded for the second as Tettey slotted the ball beyond him. Strong save down to his left denied replacement Youssef Mulumbu. 2015 Getty Images Manchester United vs Norwich player ratings Ashley Young - 5 out of 10 Cross into the middle caused panic among Norwich’s defence and allowed Martial to rifle the ball high into the net, but he was at fault for allowing Tettey to get away from him for the second goal. 2015 Manchester United FC Manchester United vs Norwich player ratings Phil Jones - 4 out of 10 Looked lost at sea when Tettey broke through to score the second after Young allowed him space, and his lack of football of late showed. 2015 Getty Images Manchester United vs Norwich player ratings Chris Smalling - 5 out of 10 Went into attack in injury time in a desperate search of goals but only conceded a free-kick when faced with a good chance to head in. Poor in defence and didn’t look comfortable alongside Jones, and to make matters worse he missed an even better chance when he headed wide when one-on-one with the goalkeeper. 2015 Manchester United FC Manchester United vs Norwich player ratings Daley Blind - 5 out of 10 Switched to left-back as Phil Jones came into the defence, which seemed odd given how reliable United have been at the back. Struggled to cope with the pace of Redmond and looked exposed on the counter attack. 2015 Manchester United FC Manchester United vs Norwich player ratings Michael Carrick – 5 out of 10 Tried to release Depay and Martial out wide but they were unable to make any in-roads towards goal. Given little to work with and was fairly average when Norwich had the ball. Getty Manchester United vs Norwich player ratings Marouane Fellaini - 4 out of 10 Completely ineffectual in the first-half and he offered no protection to the back four whatsoever as he recklessly rampaged forwards. Replaced on the hour by Ander Herrera. 2015 Manchester United FC Manchester United vs Norwich player ratings Memphis Depay - 6 out of 10 Looked to have a tap-in had it not been for some excellent defending from Russell Martin. Lacked the finishing touch and seemed to take a lot of the frustration from the United fans. 2015 Getty Images Manchester United vs Norwich player ratings Juan Mata - 5 out of 10 Wasteful cross early in the second-half summed up his performance as it went out for a throw. His drop in form has coincided with United’s six games winless streak, and his only chance at goal saw a free-kick punched clear. 2015 Manchester United FC Manchester United vs Norwich player ratings Anthony Martial - 7 out of 10 Reacted first to bury the ball into the roof of the net to give United hope. Looked the most liveliest of United’s forwards but was unable to create anything of note in the closing stages. 2015 Manchester United FC Manchester United vs Norwich player ratings Wayne Rooney - 5 out of 10 Had the ball in the back of the net early only to see the offside flag go up against Fellaini. Appetising ball from the right nearly found Depay on the last man. Attempted to replicate his overhead bicycle kickbut put the ball over. 2015 Getty Images Manchester United vs Norwich player ratings <b>Norwich:</b> Declan Rudd - 6 out of 10 Little he could do to stop Martial’s effort from close range, but he was quickly down to his left to deny Mata’s free-kick and punch to safety. Rushed off his line to put Smalling off late on. 2015 Getty Images Manchester United vs Norwich player ratings Russell Martin - 7 out of 10 Important block robbed Depay of a goalscoring chance, and he coped well given Martial and Depay were alternating wings to try and expose him on the right. 2015 Manchester United FC Manchester United vs Norwich player ratings Ryan Bennett - 6 out of 10 Looked assured as he came into the side in place of Andre Wisdom, and gave Rooney little time to work with. 2015 Manchester United FC Manchester United vs Norwich player ratings Sebastien Bassong - 6 out of 10 Easily outmuscled Mata when the Spaniard was chasing a through ball. Hardly put a foot wrong, and can be pleased with his performance after a commanding display. 2015 Manchester United FC Manchester United vs Norwich player ratings Martin Olsson - 5 out of 10 Failed to close down Young before he delivered the cross that led to Martial’s effort, but made amends when he made an important challenge to deny Depay. 2015 Getty Images Manchester United vs Norwich player ratings Nathan Redmond - 7 out of 10 Broke free on the counter to trigger the move that led to Jerome’s opener. Had a similar chance to run free in the second-half, though his cross to Tettey was too high and stopped the move. 2015 Manchester United FC Manchester United vs Norwich player ratings Gary O'Neil - 6 out of 10 Tried to bring an element of control to the Norwich midfield, but he was forced from the field with what looked to be a suspicious hamstring injury with 81 minutes gone. Replaced by Youssef Mulumbu who had a late chance saved by De Gea. 2015 Manchester United FC Manchester United vs Norwich player ratings Alexander Tettey - 7 out of 10 Calmly slid the ball past a motionless De Gea to double the lead. Looked to burst forward when United were exposed, but remain disciplined enough to sit back when his defence needed him. 2015 Getty Images Manchester United vs Norwich player ratings Robbie Brady - 5 out of 10 Booked for a foul on Mata as the United midfielder beat him to the ball. Conceded a second foul on Young that led to Rooney’s overhead-kick chance. Risked being sent-off, but managed to stay on the right side of the referee for the remainder of the game. 2015 Getty Images Manchester United vs Norwich player ratings Wes Hoolahan - 6 out of 10 Slightly starved of ball though he started to see more action in the second half. Replaced by Jonny Howson after 65 minutes. 2015 Getty Images Manchester United vs Norwich player ratings Cameron Jerome - 7 out of 10 Calmly slotted the ball above De Gea to give Norwich the lead, and seized his one and only real chance in front of goal to show a clinical finish that deserted him last weekend. Replaced by Dieumerci Mbokani with 10 minutes remaining. 2015 Manchester United FC

Mourinho, who attended Brighton’s Championship fixture against Middlesbrough on Saturday, has made it clear that he intends to make a swift return to management, with the Portuguese known to be attracted by the prospect of managing United. Although Sir Bobby Charlton criticised Mourinho’s abrasive managerial style in 2012, his reservations would not prevent the club from pursuing Mourinho should a change be made. Ryan Giggs, Van Gaal’s assistant, would also be considered as a successor and the 42-year-old could take charge of the first-team on an interim basis in the event of Van Gaal leaving his post.

Jose Mourinho watches Brighton vs Middlesbrough (Getty Images)

United’s defeat against Norwich meant the club dropped to fifth in the league, nine points adrift of the leaders Leicester City. The defender Phil Jones claims that the players, rather than Van Gaal, must take the blame for the team’s recent slump. “We have to take responsibility,” Jones said. “There’s no other way. We need to stick together and us, as players, need to take responsibility. Listen, the players in the dressing room aren’t hiding behind anyone. We know full well we have to take responsibility. The lads are absolutely fully focused on performing well for the manager, the fans and ourselves week in, week out.”

Meanwhile, the Bayern Munich chief executive, Karl-Heinz Rummenigge, thanked Guardiola for his work and confirmed a deal for Ancelotti. “We are thankful to Guardiola for all he gave our club and hope to celebrate more success in the current season,” Rummenigge said. “I am convinced that Pep and the team will work harder to reach the big sporting aims of the club, especially now that it is clear that Pep will leave.