Arsenal manager Arsene Wenger is well aware of the attacking threat of Chelsea striker Diego Costa.
The new Blues hero has already struck eight times in the Premier League since arriving from Atletico Madrid for £32million in the summer and Wenger knows his defence will have to watch him closely at Stamford Bridge on Sunday.
"He has done fantastically well," said Wenger.
"He has all the aspects of a striker that you like - he is focused, always determined and ready for a fight.
"He has also got players who can feed him like (Cesc) Fabregas and Eden Hazard, who can find him with final balls.
"Costa is a very efficient player. The timing of his runs and his determination, his killing determination - you feel he is a killer, he has that in him (when in front of goal)."
