Keane is expected to be confirmed as Villa's new coach later this month in time for pre-season training in July.
Vlaar, who is preparing for World Cup duty with Holland, believes Keane's character would boost the claret and blues.
"I don't know him as a person, I know him as a player," said Vlaar to the Birmingham Mail.
"He has a lot of fighting spirit, and I think that would be really good for us.
"He's a very strong character. I think everybody has a lot of respect for him and I look forward to it."
For the big stories and the banter follow us on Twitter: @tribalfootball