"I feel that he's back physically, with focus. I know him quite well," Wenger told British media.
"I felt he had been hit hard by us going out in the Champions League and it took him some time to recover from that mentally. I feel for a few weeks now in training he's really focussed again, and that comes out in the game."
The 28-year-old Ozil, who has suffered with illness and injury in recent weeks, is stalling on extending his current contract, which runs out in 2018, according to British media reports.
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Arsenal, who are fifth in the table, will look to secure back-to-back league wins for the first time since January when they travel to face relegation-threatened Crystal Palace on Monday.
(Reporting by Shravanth Vijayakumar in Bengaluru)
