REVEALED: The $11 million offer for Socceroos star Mooy

City is away for the fifth-round tie on Sunday (AEDT), with on-loan Mooy ineligible to take the field for Huddersfield.

Guardiola has been extremely impressed by what he has seen from the midfielder in the Championship and is open to the possibility of him playing for his side next season.

The former Barcelona and Bayern Munich boss is expecting a tough test against Huddersfield, which sits third in the second tier.

"Aaron Mooy is playing amazing," Guardiola said.

"We are going to consider what will happen at the end of the season.

"Huddersfield right now have momentum. They are playing really well, with a lot of confidence.

"They are fighting to go to the Premier League next season. I saw the game against Leeds [which Huddersfield won 2-1] - they are a really good team.

"The FA Cup is complicated but we are always fighting."

Guardiola urged some of his out-of-favour attackers to shine given star new arrival Gabriel Jesus has been ruled out for the long-term with a fractured metatarsal.

The City manager said: "Now we have had an unlucky situation with Gabriel Jesus like we had with Ilkay Gundogan and with the other players we are going to fight.

"It is not easy for the players who do not play and be out for a long, long time in many cases, like Kelechi Iheanacho, Nolito or the other players. 

"Their behaviour has been more than professional, it was perfect and [the same with] Sergio Aguero too."