Frank Lampard says Chelsea's dramatic upturn in form has transformed the Premier League title race.

Lampard struck twice in the 2-1 victory over Everton at Goodison Park that moved the Blues back up to third place and ensured they face bottom club Queens Park Rangers at Stamford Bridge looking for a seventh win in eight games.

Four successive league wins have moved Rafael Benitez's side to within eleven points of leaders Manchester United with a game in hand.

And after having dropped off the pace during a disastrous dip in form in November and early December, Lampard believes the club can once again be considered serious contenders.

"We have to keep believing," said the midfielder. "There is a long way to go and things have changed around.

"It can only happen if we win our games but if we go on performing like we have done in the last few league games and keep doing that, it's all we can do.

"We need to keep this form and this attitude."

Lampard's double at Everton highlighted the midfielder's uncertain future with the 34-year-old yet to receive an offer of a new contract despite becoming a free agent at the end of the season.

Chelsea manager Benitez has steered clear of the debate surrounding Lampard's future and faces a more immediate problem with goalkeeper Petr Cech a doubt for the visit of QPR.

Cech was replaced at half-time against Everton and Benitez said: "He felt something in his adductor so we didn't want to take any risk. We'll have to do a scan and see and this depends on the doctors."

QPR's home defeat to Liverpool left Harry Redknapp's side eight points adrift of safety although Benitez has cautioned against underestimating Chelsea's near neighbours.

"Obviously they're in a difficult position and that means they will be more dangerous," he said.

"So we have to carry on doing our job and focus on the things that we are doing well and trying to improve the things that we're not.

"It's a team that is fighting to avoid relegation and it will be a totally different challenge - we'll have to check how each player is after the tough game at Everton.

"And after that we will decide but our idea is to play in the same way, to play good football if we can, and if we can't at least show some character."

Chelsea skipper John terry is not expected to recover from a knee injury.

"He's getting closer but we have to wait and see every day when he is training with the physios and we will see," said Benitez. "I think QPR is too early for him."

Redknapp insisted after the Liverpool defeat his side could survive but admitted the forthcoming games would provide a daunting challenge.

He said: "I just believe we will stay up. I just feel we can still turn it round, if we can get one or two in now. It can still make the difference and we can do that.

"The next two games, Chelsea away and Tottenham at home are difficult games, but I still think we'll do it."

The manager will attempt to strengthen his squad in January, but admitted the continuing absence of striker Bobby Zamora with a hip injury is a major blow.

Zamora is not expected back until mid-February and Redknapp said: "If we can find the right players, get one or two in to make the difference and get Bobby Zamora fit, he would give us a target up there and he could make a difference."