LONDON (AP)

For a team at the top of the Premier League, and with a defence more than twice as effective as its nearest rivals, Chelsea are in great need of a victory over Arsenal on Sunday.

The onus would appear to be on the Gunners, since they need to trim a 10-point deficit on the leaders, but Chelsea are in the midst of a poor run of results and are facing their first real test under coach Luiz Felipe Scolari.

Since beating Sunderland 5-0 on November 1, Chelsea have won just two of six matches, been knocked out of the League Cup and stuttered badly in the Champions League.

Boost morale

Having taken just one point from home matches against Manchester United - who are at Manchester City on Sunday - and Liverpool, the Blues really need a win to boost morale and build a buffer ahead of trips to its main rivals later in the season.

"Arsenal-Chelsea's a huge game," Chelsea midfielder Frank Lampard said. "They're going to want to stay in the title race; we need to try and get a win to try and stay at the top of the table."

After a blistering start to the season, when it was routinely dismantling opponents with power, flair and skill, Chelsea seem to have finally stumbled under the affects of injuries and fatigue.

The Blues still lead the standings on goal difference over Liverpool, who host West Ham on Monday, but appear uncharacteristically vulnerable.

Toughest six months

Nicolas Anelka is still scoring goals, taking his season tally to 14 on Wednesday, but Didier Drogba is struggling after what he called the toughest six months of his career.

Drogba has not settled since he was sent off in last season's Champions League final loss to Manchester United.

Injury kept him out of action until September, allowing Anelka to replace him as Scolari's main striker, he was banned for three matches for throwing a coin into the crowd and this week was reported to have discussed a transfer to Inter Milan.

"Too many bad things have been said on me in the last few weeks," Drogba said. "I don't really want to speak about it. To be criticised, OK. But I think sometimes we need to be fair."

Off the pace

Arsenal, meanwhile, beat visiting Dynamo Kiev 1-0 to steady themselves after consecutive Premier League losses that dropped them off the pace. The club, which last won the league title in 2004, is back in fifth place and has lost five of its 14 matches.

Arsenal's form has been so poor and Arsene Wenger's judgment has been questioned over his choice of William Gallas as captain. The club's most successful manager was forced to strip Gallas of the title last week when the defender criticised his teammates publicly.