Chelsea's push for the title has hit the skids a little recently, and their grip on top spot has been reduced to just four points over nearest rivals Tottenham.

A series of niggling injuries and an alleged mystery bug running through the camp had robbed them of some key players at crucial moments, and Antonio Conte's men paid the price for it against Manchester United last week.

The Blues travelled to Old Trafford without first choice goalkeeper Thibaut Courtois, who had injured his ankle filming a promotional video with the NBA, but more trouble was coming their way before the kick off.

During the warm up Spanish wing-back was forced to pull out after he fell to being the latest victim of the bug and was forced to miss their 2-0 defeat to Jose Mourinho's side.

He since made his return to action this weekend in the 4-2 win over Tottenham that sent them to the FA Cup final, but he has now revealed the extent of his illness and what it made him do as his side went down at Old Trafford.

“I was throwing up the night before and wasn’t feeling very good. I tried to do the warm-up the following day but I was about to faint on the pitch," he said as per The Sun.

“I did not want to ask for a substitution after five minutes, so I pulled out. I watched the first half in the directors’ box but I had to go to the team coach to have a lie down on my own. I fell asleep (and missed the second half) as I was feeling so bad.

"I took a couple of days off and did not eat a lot. But I felt good against Spurs.

"I was a little bit tired in the first part of the game because it had been two weeks since I'd last played, but I'm ready for Tuesday."

Since the game it emerged that the likes of Victor Moses and Diego Costa were also suffering with the effects of the bug, with Costa in particular looking nowhere near his best.

Chelsea meet Southampton this week in a bid to get their title charge on track and Antonio Conte will be hoping that their illness troubles are well and truly behind them.

Certainly, they looked back to their best against Spurs over the weekend, though they will have to be on guard against the Saints to avoid another slip up.