For their Champions League clash, Wenger will come face-to-face with Aragones, who as Spain coach in 2004 was fined £2,000 for his infamous racist remarks to Jose Antonio Reyes about then Arsenal striker Thierry Henry.
However, the Frenchman said he had forgiven his opposite number and moved on from the incident.
"I have spoken to him since then. It was an incident on the pitch inside the training session where you can sometimes go overboard," he said.
"Having spoken to many players everybody came out for him saying he was not a racist so, of course, I have forgiven him."
Wenger also defended the Spaniard, who is under pressure just three months into his reign.
"You need time. He arrived in August and it is only October, that is very short to have an impact.
"To have an impact you need six months," said the Frenchman.