Wenger has been under the microscope after the shock FA Cup setback against Blackburn and the 3-1 first leg home defeat against Bayern Munich in the Champions League last-16 in mid-week.
Now Villa will be looking to take advantage of the Gunners' plight and bolster their chances of Barclays Premier League survival.
But Lambert is full of admiration for what Wenger has achieved in 16 seasons with Arsenal.
He said: "The level of criticism towards Arsene Wenger is a bit over the top.
"He's been there 16 years and he's just missed out on winning the Champions League against Barcelona. He's won the Premier League several times, he's won the FA Cup several times.
"If that's 'you don't know what you're doing' then I think there's something not right there, for what he's achieved is phenomenal.
"The Blackburn defeat would have been disappointing but is it a disgrace to lose to Bayern? The way they are performing and playing, no.
"It didn't surprise me Bayern beat them because of what they are doing in their own league. I think they are a right good team.
"You are talking about a team which lost on penalties in the Champions League final and potentially could go and get there again."