Former Liverpool defender Jamie Carragher believes Chelsea are struggling this season because they lack a quality centre-forward.
The Sky Sports pundit, speaking after the Blues' suffered a surprise 2-1 defeat to Swiss champions Basel in the Champions League, says Chelsea look as if they're playing with 10 men this season.
"Virtually every game I've seen Chelsea in, they are playing with 10 men," Carragher stated. "No matter how many players you've got if you haven't got a centre-forward who's a top striker, a lot of it falls down."
Samuel Eto'o started in attack for Chelsea against Basel on Wednesday night, but the Cameroon international failed to hit the back of the net in his second appearance for the club.
Jose Mourinho brought the 32-year-old to Stamford Bridge to provide additional competition for Fernando Torres and Demba Ba, while the Portuguese coach opted to send Belgium international Romelu Lukaku on loan to Everton for the season despite his impressive performance at West Brom last term.
"[Mourinho's] tried them all - even went with no striker at Old Trafford, Carragher added. "He's tried everything but it just doesn't work."
Chelsea, who were also beaten by Everton at the weekend, have won two matches since Mourinho returned to the club in the summer.