The Citizens are sitting at the top of the Premier League table following a brilliant start to the 2017-18 season.
Manchester City have won 12 of their opening 13 fixtures and only Everton have managed to deprive Guardiola’s men of a 100 per cent record.
Chelsea are unbeaten in their last five outings to maintain their nine-point deficit behind the Eastlands outfit.
Manchester United were level pegging with their city rivals at the start of the season before a disastrous October which saw the Red Devils collect four points from four games.
The Red Devils’ unbeaten start to the campaign lost 2-1 to promoted side Huddersfield Town before a 1-0 defeat at defending Premier League champions Chelsea at Stamford Bridge.
Jose Mourinho’s men were 4-2 winners against Watford at Vicarage Road on Tuesday night to temporarily move to within five points of the runaway leaders.
Former Liverpool FC defender Thompson believes Chelsea and Manchester United will struggle to challenge Manchester City for the title.
“Chelsea and Manchester United look to have enough to be in the top six but without quite a few injuries to key personnel, perhaps Kevin De Bruyne and David Silva, the creative spirits of the side, or another centre-back, you can’t see anyone getting close to City,” Thompson told Sky Sports.
Chelsea won the Premier League title with two games to spare last term to win their second top-flight crown in three seasons.
Manchester United finished in sixth place in the Premier League table.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news