Guardiola says United a better team than the one City hammered months ago

(Reuters) - Manchester City face a far different Manchester United than the one they thrashed 6-3 in October, said manager Pep Guardiola, adding his side have to be at their best in the FA Cup final on Saturday.

Guardiola's City face Erik ten Hag's United in not just an historic first FA Cup final between the Manchester rivals, but the second of three boxes City need to tick in their quest for the treble.

"What Manchester (United) are doing in the last five or six months, they're a completely different team to what we faced at the beginning of the season," Guardiola told a press conference on Friday.

"Finals are all about how you will be in the 90 minutes, in that moment," he added. "It's not what you have done in the past or how good you are. It's one game, so we have to be our best to beat them."

City, who were all but unbeatable in the final weeks of the Premier League season to win their third consecutive title, take on Inter Milan in the Champions League final - the one trophy City have yet to claim - on June 10 in Istanbul.

Guardiola said his team are fit and healthy for Saturday's clash at Wembley. Kevin De Bruyne and Jack Grealish "trained well" in the last two sessions, he said, and Stefan Ortega will keep his place in goal after starting throughout City's FA Cup campaign.

City are on a quest for a treble only achieved by one other English club - Manchester United in 1999 - and Ten Hag's team would love nothing better than spoiling City's dream.

Guardiola had kind words for the Dutch manager's impressive work, guiding Man United to the League Cup in February and a third-place finish in the Premier League in his debut season.

"I cannot say we are friends... but he represents our profession as a manager in the best way possible. I think Man United has an exceptional manager for many years," the Spaniard said.

With numerous games being decided by a penalty shootout this season, including Sevilla's win over AS Roma in the Europa League final on Wednesday, City are prepared for Saturday's game to be decided that way.

"The most important skill is the mentality," Guardiola said.

City are seeking a seventh FA Cup while United are in the hunt for their 13th.