Arsenal striker Olivier Giroud is starting to become a bit of an "animal", according to manager Arsene Wenger.
The French forward has scored a dozen goals in his last 12 appearances, helping the Gunners climb back up the Barclays Premier League table.
Giroud, who missed three months earlier in the campaign because of a broken leg, felt he needed to be less emotional and add a "killer attitude" to his game, similar to that of Chelsea striker Diego Costa, who has helped fire the Blues towards the title and could lead the attack against Arsenal at the Emirates Stadium on Sunday.
Wenger believes 6ft 4in French international Giroud is now showing just what a powerful, all-round centre-forward he can be.
"Olivier Giroud has a fantastic body strength... and sometimes he needed to be challenged really physically to become really that animal he can be," said Wenger.
"He has the kind of game which is linked with his back to goal, protection (of the ball), so he gets hit a lot, sometimes that game demands as well more commitment and toughness.
"But on the other hand, Olivier Giroud is a player who has improved tremendously technically.
"You take some pictures of Olivier Giroud when he arrived, and today he is a different player - let's not forget this guys is 92kgs, when he walks on your feet, you feel it."
Former Arsenal captain Cesc Fabregas is set to return to face his old club for the first time since joining Chelsea in the summer from Barcelona.
Much has been made of the suspected reasons behind the £30million transfer to Stamford Bridge rather than seeing the Spain international head back to the Emirates Stadium instead.
Wenger is, though, "extremely happy" with the club's completed summer transfer of being able to sign Alexis Sanchez, adding to an already talented attacking pool.
"(There is) congestion as well. We don't only have Sanchez and (Mesut) Ozil, but also (Jack) Wilshere in this position, (Alex Oxlade) Chamberlain, (Aaron) Ramsey, all offensive players," he said.
"When you have to spend £35m to £40m for a position where you already have players, you have to question what is the logic?"
Wenger added: "When a big player goes from your club, everyone says 'you have to buy another one with the same qualities'. Once he has gone you have brought another one with the same qualities, he wants to come back and it is not obvious to spend so much on a position that is exactly the same.
"Where does Cesc play today? Behind the striker. Where does Ozil play? Behind the striker."