John Terry believes that Chelsea being on the receiving end of Guus Hiddink's boot in recent weeks has been key to their revitalised form. The team have won six of their seven matches since Hiddink was appointed last month, with Terry revealing yesterday that several of his team-mates have benefited from a kick up the backside from the interim manager.

Hiddink is far more demanding than Luiz Felipe Scolari, his predecessor, having introduced stricter disciplinary procedures, made the players work much harder in training and urged them to take greater personal responsibility for their performances. The Dutchman extended some leeway to his squad yesterday by giving them two days off, although several reported for duty anyway.

Didier Drogba's knee was given the all-clear after a scan and the Ivory Coast striker should be fit to resume training with his team-mates tomorrow, while Deco will have a scan today after the swelling has gone down on his hamstring, having limped off after 40 minutes of the victory over Manchester City on Sunday.

“Since the new manager has come in here we've played very well and got the right results,” Terry said. “He has changed a few things, given a few of us a kick up the backside which I think we needed.”

Chelsea's changed attitude has enabled them to reach the Champions League quarter-finals and the FA Cup semi-finals, as well as re-emerge as genuine Barclays Premier League title contenders, four points behind Manchester United. Terry believes that Chelsea can push the champions all the way, just as they did last season when, after streaking ahead, United had to beat Wigan Athletic on the final day of the season to be sure of retaining their title.

“We've got to win our games and push them right to the end,” the Chelsea captain said. “We have shown our strength and character in the last month, and if we keep doing that we can apply some pressure to them. If they slip up, they know we're coming up behind them.

“Man United have good players, but after a big defeat like they had to Liverpool last weekend you never know how they're going to react. Hopefully they're going to go on a bad run, but the main thing for us to do is to keep winning and applying the pressure.”

In addition to the Hiddink effect another unquestionable factor in Chelsea's revival has been the return from injury of Michael Essien, the dynamic Ghana midfield player. Essien has scored a crucial goal in each of the matches in which he has started since returning from knee ligament damage, a remarkable feat given that he had been out for six months.

“Only Michael could do that,” Terry said. “Only he could come back and after two games have scored two goals and play as well as he has been. After so long out you think it would take three or four games to find his feet, but he is an absolute machine.

“You see him working his socks off for six months in the gym and it pays dividends. He is brilliant and it's great to have him back.”

Essien's energy brings an added dimension to the midfield and gives Hiddink a plethora of options, leading Florent Malouda, the winger, to claim that his team-mate can make the difference to Chelsea's title challenge.

“You can see his energy and spirit is coming back to the team so it helps the strikers because he is running and running and keeps on running,” Malouda said. “He has a positive attitude and gives a lot of confidence to the team.

“Essien can make the difference because when you spend five months injured you have this commitment and want to prove that the time you spent on the sidelines is not a lost time. We're still trying to win three trophies, we will have a lot of games and Michael gives us the right spirit.”