LONDON - Although it's only early November, Chelsea and Arsenal face crucial tests this weekend to prove they'll play any part in the Premier League title chase.
The London rivals are already nine points off the pace but can close the gap when they take on the Manchester duo that tops the table on Sunday.
Manchester City are front-runners on 28 points followed by Manchester United (23), Tottenham (22) and then Chelsea and Arsenal (19 each).
Arsenal get the first chance to lay down a marker when they visit City, followed by defending champions Chelsea hosting United.
"This is a must-win game," Chelsea goalkeeper Thibaut Courtois said. "We must win games like these to remain at the top and close to the other ones. We will try to get the three points and will give our lives for it on Sunday."
Chelsea must quickly rebound from a disastrous Champions League trip to Italy on Tuesday where they fell behind after just 38 seconds and were totally outclassed by Roma 3-0.
United, meanwhile, made it four wins from four in Europe by beating Benfica 2-0 and midfielder Nemanja Matic says they'll need the same effort against his former side.
"We know we must respect them," Matic, who joined United from Chelsea in the summer, said. "They are a good team, they're champions and it's going to be a hard game for us, but we also have our own qualities."
Arsenal will definitely have to be at their best if they're to stop the early season juggernaut that is Man City.
Pep Guardiola's side have won nine and drawn once in the league, outscoring the opposition 35-6.
They're also unbeaten in 16 games overall following a win at Napoli on Wednesday that sent them into the Champions League knockout stages.
A sidebar to the match will be Alexis Sanchez, who looked set to leave Arsenal for City before a summer deal fell.
Though he's still being linked with a move away either in January or after his contract expires next summer, manager Arsene Wenger isn't doubting his star's commitment.
"I think he's coming back stronger physically," he said. "He runs after a goal at the moment so he's a bit frustrated when he doesn't score.
"I'm not worried about it. He works hard and it will come back quickly."
Tottenham look to carry the impetus of a Champions League win over Real Madrid into their game against last-placed Crystal Palace.
Spurs were masterful in beating the holders 3-1 to qualify for the last 16 but manager Mauricio Pochettino afforded himself little time to savour the victory.
"It's an unbelievable performance, a great victory and now it's important to enjoy it," he said. "But we're already thinking about an early kick-off on Sunday and a tough game against Palace."
Stoke host Leicester, West Brom visit Huddersfield, Newcastle meet Bournemouth, Burnley are at Southampton, Swansea face Brighton, Liverpool are away to West Ham and Everton take on Watford in the weekend's other games.