Manchester City midfielder Phil Foden says he now feels 100 per cent fit after overcoming "one of the worst parts of my career".

Foden, who scored twice in Tuesday night's 3-0 win over Championship side Bristol City to send City into the FA Cup quarter-finals, struggled with an ankle injury after the World Cup and lost his spot in the team.

But, after scoring three goals in his last two games, Foden is now hitting his stride at the right time as second-placed City chase leaders Arsenal in the Premier League title race and pursue glory in the Champions League and FA Cup.

"I feel much better with my feet," Foden told ITV. "I feel 100 per cent fit now and comfortable. It has been one of the worst parts of my career but everyone goes through them and it is how you react.

"[The issue was] discomfort in my feet and not playing as much. I love to play football and when I don't I am a bit frustrated."

Ahead of Saturday's win at Bournemouth, Foden had started just three of City's previous 10 Premier League matches.

Guardiola explained on Friday that Foden's month-long absence after the derby defeat at Manchester United was because he needed time to recover from his ankle injury with the subsequent form of Jack Grealish and Riyad Mahrez extending his time out of the team.

But the Man City boss was clear in his support of Foden, saying "Phil is our diamond", and Guardiola's show of faith has been rewarded with three goals in the wins over Bournemouth and Bristol City in the space of four days.

"His career was always up, up, up," Guardiola added of Foden, who had won two Premier League titles at 19 years old. "This season he struggled a bit and was a bit down. But now he's back for the best bit of the season."

"His impact has been amazing. Football pays off when you work like he does."

City faced a spirited Bristol City display on Tuesday night at Ashton Gate and were only leading by one goal heading into the final 20 minutes of the game, before Foden and Kevin De Bruyne added late gloss.

Guardiola was full of praise for the Championship side, five years on from facing them in a two-legged League Cup semi-final.

"It was really tough," said Guardiola. "Bristol showed us how good they can be. I was impressed by some players, I didn't know them. The second half was much better.

"Incredible fans at Bristol. We came here five years ago in the Carabao Cup and it was amazing. I remember it perfectly."