Pep Guardiola said John Stones had proven he belongs at Manchester City after a derby win over United in the EFL Cup semi-finals.
Stones scored his first City goal since November 2017 and Fernandinho sealed a 2-0 win at Old Trafford on Wednesday as the three-time defending champions booked a spot in the final against Tottenham.
The City defender, who was relieved to see the flag raised after the ball bounced off him and into his own net during the semi-final, has been in good form this season, and his six possessions gained against United were the equal best for his side.
City manager Guardiola was full of praise for Stones, who had appeared on the outer at the club before beginning to impress.
"He came back and he made another outstanding performance – but the most important thing is he can do something he hasn't been able to do – play four, five, six games in a row. This is important," he told a news conference.
"He had to handle [Marcus] Rashford, who is dangerous and clever, and the quality of his passes to Joao [Cancelo] were outstanding. All the team, Fernandinho, our captain, what a performance again. He read the game incredibly well, he moved the team. Outstanding.
"All the players – [Ilkay] Gundogan, Raheem [Sterling], Phil [Foden] ... all the team."
Guardiola added: "All credit [to Stones]. Football is a long career – it is up and down, sometimes bad moments. He was out longer than we expected but he came back and he absolutely belongs here.
"We can help him but when someone plays like this, it's credit to him. Hopefully he can continue in this way."