Roy Keane believes Manchester United's shock FA Cup fourth-round defeat to Middlesbrough on Friday evening will increase the pressure levels on their upcoming fixtures.
Following the winter break, United resumed their campaign as strong favourites to get the better of the Championship side and book their place in the fifth-round of the cup.
However, following a 1-1 stalemate at the end of 120 minutes, Middlesbrough brought United's hopes of winning a domestic trophy for the first time since 2017 to an end, winning 8-7 in a tense penalty shootout.
The defeat means interim manager Ralf Rangnick and his players now have the challenge of getting back to form, starting with Tuesday evening's Premier League tussle with Burnley at Turf Moor.
Keane said United's defeat to Chris Wilder's side will change the mood around the club and believes the Reds now have yet more pressure weighting on their shoulders.
"You have to be critical of Manchester United," Keane told ITV Sport. "[In the] first half, they were fantastic, but they are playing a Championship team at home in the cup.
"Obviously, it's not good enough. Defeat changes the mood. It changes the mood in the ground as well.
"The fans would have been thinking they would win tonight [Friday] and, being at home, I fully expected them to beat a Championship team.
"But now, it just adds more and more pressure to the upcoming games."
February promises to be a key period in United's season, with another six games to come before the end of the month, including a trip to arch rivals Leeds and the first-leg of their Champions League last-16 tie with Atletico Madrid.
Although the defeat to Boro was the far from ideal way to start the month, Rangnick is confident his players will not need too much motivation to bounce back.
"Physically, I don't think we need to lift the squad,'' said the United boss. "With Paul [Pogba] having been out for two and a half months, it was normal that he was substituted after 65, 70 minutes.
''Jadon [Sancho] had no injury, he was just feeling some fatigue and had some cramp so that was the reason why we decided to take him off.
''Of course the players are disappointed like we all are but again this is football, this can happen.''
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