The Red Devils played out a goalless draw with La Liga side Valencia in the Champions League on Tuesday night to heap more pressure on Jose Mourinho.
The Manchester United manager has endured a difficult start to the Premier League season following three losses in seven outings so far.
Mourinho’s men played out a 3-1 loss to West Ham United at the London Stadium last weekend to leave the Red Devils in tenth place in the table.
Manchester United will be concerned about their start to the season in light of losses to Brighton, Tottenham Hotspur and West Ham.
The Red Devils are already in tenth place and nine points behind the Premier League leaders Manchester City with big games against their title rivals to come in the next few months.
Reports in the British media have claimed that both Paul Pogba and Antonio Valencia are at odds with the Manchester United manager following public criticism of the pair.
Alexis Sanchez was also thought to be unhappy at his omission for Manchester United’s loss to West Ham at the London Stadium.
Former Manchester United captain Keane slammed the behaviour of the Red Devils squad ahead of their clash against Newcastle this weekend.
“Players who get upset with a manager, or coaching staff, and think ‘I’m not going to train properly because somebody upset me’ – there’s a lot of cry babies out there, lots of cry babies,” Keane told Notts TV, as quoted by the Daily Mail.
“When you walk out on that pitch, you’re playing for your pride, you’re playing for your family, you’re playing for your city, whatever it may be. Don’t get that worried about what the manager said about you or the coaching staff. You get out there and play.
“You can fall out after the match, but when the game’s going on, liven up, play with pride, play with energy, play with spirit. Hopefully play with a bit of skill, but you can’t always play with skill, you can have a bad day, but on your bad days you roll up your sleeves and you fight for that jersey and don’t get distracted by the balloons out there.”
Keane, though, had his run ins with management during his Manchester United and Republic of Ireland career.
The former Red Devils skipper famously left the Republic of Ireland camp just days before the 2002 World Cup in Japan and South Korea.
Keane was unhappy with the training facilities in Saipan ahead of their group-stage opener against Cameroon.
His well-documented clash with Republic of Ireland manager Mick McCarthy proved a decisive issue amongst the Irish people.
Keane was a stalwart under Sir Alex Ferguson for 11 seasons but his time at Old Trafford came to an end in 2005.
You can fall out after the match, but when the game’s going on, liven up, play with pride, play with energy, play with spirit
The former Republic of Ireland captain blasted some of his under-performing Manchester United team-mates in an interview with the club’s in-house channel.
Keane parted company with Manchester United to move to Celtic before retiring at the age of 35.
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