London - Arsene Wenger believes Mesut Ozil's recent resurgence is down to the Arsenal playmaker's improved fitness levels.
Ozil was outstanding in last weekend's north London derby victory over Tottenham Hotspur and will again play a key role as Wenger's side attempt to build on that win when they travel to face Burnley on Sunday.
The Germany international, who is in the final year of his contract at the Emirates Stadium and could open negotiations about a move away in January, came in for heavy criticism during the Gunners' stuttering start to the campaign.
But his improved recent form has demonstrated the player's quality and Wenger attributes this to Ozil's efforts on the training ground.
"Mesut has worked hard and he is extremely fit at the moment as well, and that is why you see him sharp," the Arsenal manager told the club's official website.
"The quality of his technical aspect is always there but he has added a more determined attitude and that is what you want from him."
Veteran French boss Wenger added: "Football today is very demanding in the mental and physical aspects and Mesut is in much better physical shape than he was before.
"Every player wants to be a star and when they don't manage to do it they are really disappointed but the best way to achieve it is to work hard and show the quality of performance that people expect from you."
Last weekend's win left Arsenal in sixth place, a point behind fourth-placed Tottenham with goal difference alone keeping the Gunners above Burnley.
Wenger has been impressed by Sean Dyche's side this season and is well aware of the test that lies ahead for his team.
"They are the surprise package because before the season if you asked 100 people if Burnley would have 22 points at this stage of the season, 90 would have said no - and the 10 others would have been Burnley supporters," he said.
"They have won games with 25 percent or 30 percent possession, that means they are calm, they know what to do and they are patient with that killing instinct of a snake," Wenger added. They put you to their face and then they bite you."
Wenger will restore his first choice line-up after making wholesale changes for the midweek Europa League defeat at FC Koln which did not prevent Arsenal from continuing in the competition as group winners.
Danny Welbeck will return to the bench after a 45-minute appearance against the German side but Theo Walcott is out because of illness, while Santi Cazorla remains a long-term absentee.
Burnley are boosted by the return of top goalscorer Chris Wood for their clash with Arsenal after the striker missed last week's victory over Swansea City.
Wood returned late from New Zealand international duty with a minor hamstring problem ahead of the win over the Swans, but has since got through a full week of training.
Burnley manager Dyche has no fresh injury concerns, although England goalkeeper Tom Heaton is still recovering from a dislocated shoulder.
Dean Marney (knee ligament) and Jonathan Walters (knee) have both returned to training but are not ready to be brought back into the matchday squad.
Speaking ahead of Sunday's clash, Clarets boss Dyche said: "When you come across these clubs, it's a case of how you are performing against some of the most powerful teams - not just the score, but the actual performance level.
"Playing against these big teams is a measurement of where we are in relation to them."