Ryan Giggs believes Chelsea pose the biggest title threat to Manchester United, not Manchester City.
The huge spending by billionaire owner Sheikh Mansour has propelled City into the title race, after years in the shadow of their near neighbours.
The Red Devils are only above their city rivals at the summit of the Premier League on goal difference after a flying start to the season by both teams.
However, while Giggs acknowledges City have some world-class stars, he feels Chelsea represent the biggest challenge as a team.