Arsenal midfielder Samir Nasri says Chelsea are weaker than last season.

The 23-year-old is optimistic about his team's chances of taking the championship off a Chelsea team with little back-up when their key players are missing, as they were against Sunderland on Sunday.

"The absence of John Terry, Alex, Michael Essien as well, that made a big difference," he said. "Chelsea have lost [Michael] Ballack, have lost Deco in the midfield, Ricardo Carvalho also and they haven't really replaced him. So much the better. Their first-choice XI is good but the group I think has lost a bit in terms of quantity and quality compared to last season.

"It was an ideal weekend with Chelsea's defeat, Manchester United's draw at Aston Villa, Manchester City's draw against Birmingham. We're second, it's something that's exciting for the future. We're really in it, very close to the top."