The European champions had a superb start to their top flight campaign this season and were tipped to be among the favourites to win the title, alongside Manchester City and Liverpool.
However, the Blues have struggled to get results on the pitch in recent league outings and have not managed to get back-to-back wins since November, falling to third in the standings; six points behind leaders Manchester City and three behind second placed Liverpool.
Former Premier League star O’Hara has insisted that the Londoners are not part of the title race any more as the Reds and Citizens have pulled ahead and are now favourites for the top flight crown.
O’Hara admitted Chelsea have had to deal with injuries to key players but stressed that they have lost that X-factor that both Manchester City and Liverpool still have.
“I do not know about Chelsea; I do not know”, O’Hara told talkSPORT while discussing the favourites to clinch the Premier League title.
“I think they might be going to fall away.
“I think it is a two-horse race.
“Yes, Liverpool and Manchester City for me [are the favourites].
“I do not know, Chelsea are going through a real sticky patch and I know that they have got so many injuries, but I do not know, I feel like they’ve lost something that Manchester City and Liverpool have got.”
All three of Chelsea, Manchester City and Liverpool are in top flight action on Boxing Day, taking on Aston Villa, Leicester City and Leeds United, respectively.