Defender Aymeric Laporte and midfielder Fernandinho were substituted and Guardiola said they were unlikely to be back in time for the home leg of City's last 16 Champions League tie on March 12 against Germany's Schalke, which his side lead 3-2.

The Spaniard added that City, who beat Chelsea 4-3 on penalties after Sunday's showpiece fnished 0-0 following extra time, would be tired when they resume the chase of Premier League leaders Liverpool at home to West Ham United on Wednesday.

He said other clubs challenging for the Champions League were not competing in two domestic cup competitions and the strain was starting to show on his players.

"I am impressed how they (City's players) can play games and games and games and not have injuries, but in the end it is happening," he said.

Manchester City are still in the FA Cup - they face second-tier Swansea City in the quarter-finals next month -- as well as chasing the Premier League title and the Champions League.

Guardiola played down the significance of Liverpool being held to a 0-0 draw by Manchester United in the league earlier on Sunday which put the Anfield club just one point ahead of City.

"Still they are leading, still they are the favourites," Guardiola said.