Mourinho has come in for criticism this term with United sat seventh after 11 games, nine points off league leaders Manchester City .
But Wenger told beIN Sports: "It looks to me that against Everton and Bournemouth he turned his team on the right side in terms of the performance.
"His team was down and responded twice in a very positive way. Overall you can trust his quality and experience to get Manchester back on track."
Asked if there had been a change in Mourinho's approach this term, the Frenchman added: "'I don't see him working everyday so I don't know if he has changed or not.
"We had very heated confrontations so for me I don't think his motivation has dropped."