Yaya Toure has challenged Manchester City to put a smile back on Pep Guardiola's face with a dominant display in Friday's FA Cup third-round clash at West Ham.

Guardiola was in a tetchy mood following City's 2-1 win over Burnley on Monday as he grumbled about the way officials treat his team and embarked on a series of fractious post-match interviews.

Adding to the growing sense that the City boss is struggling to find his feet in English football, in a recent interview with NBC he said he may not stay in management for much longer than his current contract.

Although Guardiola won trophies and plaudits by the bucketload during his spells at Barcelona and Bayern Munich, managing those clubs comes with a guarantee of success to a certain degree.

In contrast, the more cut-throat Premier League, where Leicester's title triumph last season showcased a strength in depth missing in Spain and Germany, can sap a manager's vim.

While it is far too soon to say Guardiola's philosophy won't succeed in England, he certainly looks frazzled and could do with City -- lagging well behind Chelsea in the title race -- recapturing the swashbuckling spirit that saw them mark his arrival with a long winning streak.

City midfielder Toure, back in favour after clashing with Guardiola earlier this season, believes the solution is to play with more passion at critical moments.

"At the moment we are in not in our best form but we have to be able to deliver," Toure said.

"City have always been a team who fight to the end to win a trophy and at the moment we are not happy with the position in the league. We have to fight.

"We are starting the second half of the season now and I think we will have to be almost perfect.

"We'll have to win all the games when we play the top four. The lads, the fans, the manager, we are all understanding that and we will try to do our best to get there."

Confidence

Guardiola's first taste of the FA Cup comes at the London Stadium, where inconsistent West Ham will hope to bounce back from successive league defeats against Leicester and Manchester United.

Hammers goalkeeper Darren Randolph is confident his team's gritty effort against United following Sofiane Feghouli's controversial red card, which has since been rescinded, offers hope.

"We battled on for most of the game with 10 men, still creating chances, so we take confidence from that," Randolph said.

Chelsea manager Antonio Conte will also be competing in the FA Cup for the first time when the Premier League leaders take on third-tier Peterborough at Stamford Bridge, while title rivals Liverpool face fourth-tier Plymouth at Anfield.

Holders Manchester United will be aiming for their eighth successive victory in all competitions when they host Championship promotion chasers Reading.

Arsenal, who lifted the FA Cup in 2014 and 2015, travel to second-tier Preston looking for a more complete performance after they were forced to fight back from 3-0 down in a dramatic 3-3 draw at Bournemouth on Tuesday.

Among the non-league minnows aiming to cause a surprise are Eastleigh, who face second-tier Brentford, Barrow, at home to third-tier Rochdale, and Sutton, who entertain third-tier AFC Wimbledon.