Pep Guardiola has said not even winning the FA Cup can save Manchester City's season.

City booked their place in the quarterfinals with a hard-fought 3-1 win over Plymouth Argyle at the Etihad Stadium on Saturday.

Guardiola's team have reached the last eight of the competition for the seventh year in a row. But he admits not even lifting the trophy will make up for relinquishing the Premier League title and their early exit from the Champions League.

"It's better to win the treble or quadruple, come on," said Guardiola.

"This season, especially in two competitions, we've not been good. And that's the reality.

"We didn't qualify for the first time [for the last-16] of the Champions League since we are here, and in the Premier League with 13, 14, 15 games left we have no chance of winning [the title]. It's never happened. The season has not been good."

City had to fight back from a goal down against Plymouth, conquerors of Liverpool in the last round, after Maksym Talovierov gave the Championship side the lead.

Nico O'Reilly, playing as a makeshift left-back, equalised just before half-time and added a second after the break. Kevin De Bruyne wrapped up the result with a third goal in the final minute.

O'Reilly, 19, was the subject of interest from Chelsea in the January transfer window before City decided to rebuff a late bid.

"Sometimes you take a good decision, otherwise he would not score two goals today," said Guardiola.

"He's not a typical academy player. He's a physical presence, a number 10, I would say. He can play in a few positions. He's a threat from set pieces because he's strong. I'm really pleased for him because he helped us a lot."