Reports originally broke on Monday suggesting the 23-year-old was poised to undergo a medical with the Serie A giants, and now Wenger has just stopped short of subtiantiating the claims that the deal includes an option for Milan to sign him permanently at the end of the 2008/09 campaign.
Wenger told Sky Sports News: "Senderos has gone to Milan today and is not available anymore.He will go to Milan. He will complete a medical today.
"The thinking [behind the move] is that at the moment he doesn't get the games here and that he can play somewhere and remain in a top level club.
"Without losing him we want him to play. It (whether the transfer will become permanent) is not decided yet," he added.
"For us, we have Johan Djourou, Kolo Toure, Senderos, Alexandre Song, William Gallas and Mikael Silvestre, who can play centre-back, so there is congestion there."
Wenger concluded by casting an eye one the upcoming Champions League qualifier against Steve McClaren's Twente, revealing that star midfielder Cesc Fabregas could play a part in the crucial encounter at the Emirates.
"He is in the squad," confirmed the Gunners boss. "I cannot tell you whether he will start or not. He is ready to start."
Derek Wanner, Goal.com