Rio Ferdinand claims Ruben Amorim decision vs Arsenal will have left Manchester United star unhappy

Rio Ferdinand has heaped praise on Manchester United youngster Toby Collyer for his eye-catching cameo in Sunday's FA Cup triumph over Arsenal, but he thinks the decision to bring the youngster on ahead of Casemiro will have frustrated the Brazilian.

Collyer stepped off the bench with 81 minutes on the clock to make his first appearance since September and played a key role in helping United, who had already been playing with 10 men for 20 minutes, take the contest all the way to penalties.

He replaced Kobbie Mainoo in the centre of midfield and was instrumental in helping the Reds reach the fourth round and book a date with Leicester City at Old Trafford next month.

Collyer was the most inexperienced player in Ruben Amorim's matchday squad, yet the United head coach turned to him and not Christian Eriksen or Casemiro when he decided to make a change in midfield.

The determination and desire that Collyer demonstrated quickly made it easy to understand Amorim's thinking. Ferdinand, speaking on his YouTube channel, said: "Toby Collyer was excellent when he came on, the energy levels were huge, through the roof. Testament to him."

Collyer's cameo in north London marked his first appearance under Amorim. And Ferdinand believes the fact he got selected ahead of Casemiro will have the Brazilian thinking about his future.

Ferdinand continued: "Is the player happy to be on the bench? I don't think Casemiro will be happy. At any point in his career he's never been on the bench.

"So if he's on the bench now, if an offer came in, he'd listen to it. But also the club, you can see now they are bringing on Toby Collyer. If they get an offer they require (for Casemiro), that they want, I don't think it will be something that will be