Chelsea manager Guus Hiddink says Michael Essien will make the difference to their title and Champions League hopes now that he is finally back in first-team contention after six months out.
Essien played the full 90 minutes for the reserves on Monday night in what was his first game since the midfielder suffered a serious knee injury in September.
The Ghana international showed no discomfort and even scored in the 4-3 defeat at Aston Villa, which was watched by boss Hiddink.
The Dutchman is delighted to have Essien back and said:''His return will make a huge difference now we're going into a decisive month.
"I've also seen him in training sessions and he's very close to playing in the first team.''
While Essien did not feature at Portsmouth on Tuesday night, he could be in contention for the FA Cup quarter-final against Coventry on Saturday, or the Champions League tie with Juventus next week.