Rio Ferdinand has been left puzzled by Ruben Amorim's tactics following Manchester United's recent loss to Crystal Palace.

Ferdinand, who spent 12 years at Old Trafford, reacted to United's 2-0 loss at home to Crystal Palace on Sunday as a Jean-Philippe Mateta brace condemned his former side. Amorim chose to start without Joshua Zirkzee or Rasmus Hojlund for the clash with the Eagles by handing the forward responsibility to academy graduate Kobbie Mainoo.

Mainoo, who scored and assisted in United's 2-0 win over FCSB just days ago was largely ineffective as a forward in the 3-4-2-1 system. United had been linked with a deadline day move for Bayern forward Mathys Tel but it now appears as if their efforts will be shifted elsewhere following news relayed last night by The Athletic.

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"Kobbie playing up front, another new variation of tactics from the manager," Ferdinand said, reflecting on Amorim's change in personnel. "There's two strikers - where does that leave Zirkzee and Hojlund? I see that we're in the market for the young Bayern Munich striker (Tel) now. He's a great talent but do we need another young one?

"Maybe we do, the manager maybe sees that we're in the market to get him. But when you play Kobbie so high, Bruno has to play even deeper. Then we lack that real threat. We weren't really a threat today."

Further moves for Aston Villa's Leon Bailey and Chelsea star Christopher Nkunku have also been mooted but look unlikely despite United allowing Marcus Rashford to move on loan to Aston Villa for the remainder of the season. Amorim kept tight-lipped on the situation in his post-match press conference on Sunday, insisting there is still work to be done.

"We are trying everything to improve the team without making the mistakes of the past and also trying to balance the urgency of the moment," said Amorim. "We know all of the aspects of our club in the moment but we are trying everything.

"This market is really hard on clubs to make some deals. I want to improve the team so badly. I know what the team needs. Sometimes it's possible, sometimes it's not. When the window closes we will see the players that we have."

Amorim said on Sunday the club will "try everything" to sign a forward. But the Manchester Evening News understands no prospective deal is currently developing and sources have stressed United have no intention of recruiting any short-term or stop-gap players who could compromise the club's budget in the summer.