Five things to know about this weekend's Premier League matches: ___

CHELSEA'S BLUES

The delirium that greeted Jose Mourinho's return to Chelsea after six years has not been matched by results on the field. "When we lose, I am the responsible (one)," Mourinho said, reflecting on the worst start to a season in Roman Abramovich's decade as owner. Chelsea's first Premier League loss at Everton on Saturday was followed Wednesday by losing the team's Champions League opener to FC Basel 2-1. Although there's little danger of his love affair with the fans ending soon, there's little margin for error for Mourinho in Saturday's west London derby against Fulham. Six games into the season and only a single goal has been scored by a Chelsea forward. Even then, Fernando Torres' goal only came in the far-from-meaningful Super Cup loss to Bayern Munich. The Spain international didn't even make the squad for the match against Basel, while fellow forward Demba Ba only came off the bench. Mourinho seems to be favoring Samuel Eto'o, although the Cameroon striker hasn't found the net in his two games since joining from Anzhi Makhachkala. Eto'o was the highest-paid player in the world at Anzhi, and Mourinho said he was at the Russian club "not for the right reasons and you lose hunger and appetite." ___

MANCHESTER DERBY

The other derby this weekend pits the top two teams in the last two seasons on Sunday. Defending champion Manchester United and 2012 league winner Man City have the same record as Chelsea after four games — two wins, a loss and a draw — although both enjoyed bright starts to the Champions League. The big intrigue at United centers on striker Wayne Rooney, who scored two in Tuesday's 4-2 win over Bayer Leverkusen. Even after taking his United goal tally to 200, though, Rooney couldn't bring himself to commit his future to the club after being denied a move in the offseason. ___

LEADING LIVERPOOL

The pacesetters remain the team that hasn't won the title since 1990, although Liverpool isn't starting to plan the celebrations for a 19th English title. The Reds host Southampton on Saturday after seeing their perfect start end with a draw at Swansea on Monday. ___

NORTH LONDON RIVALS

Can Tottenham and Arsenal keep up their strong starts? Both have three wins out of four so far. Arsenal next takes on Stoke on Sunday, while Tottenham heads to Wales to play promoted Cardiff. ___

ELUSIVE VICTORY

The bottom two, West Bromwich Albion and Sunderland, are the only teams yet to win. They meet on Saturday at the Hawthorns.