The Scot's job security has come into question in recent weeks following a run of poor results and owner Randy Lerner's decision to put the club up for sale.
And Villa captain Vlaar is unaware if the former Norwich City boss will remain at the club.
"I have no idea to be honest," he is quoted as saying by the Birmingham Mail. "I know the rumours but what can I say? We will wait to see what is happening.
"As players we have to look to ourselves and we realise it has to be better. We have to do our things on the pitch.
"I think he has been very important up until now.
"The last few months were really hard for everyone but we made it."
Villa lost seven of their last nine fixtures as they ended the season in 15th position in the Premier League, just five points above the relegation zone, and Vlaar admits his side were lucky to stay up.
"We should be happy the season isn’t two or three games longer because we were in big trouble," he added.
"We have a summer to recover. We all realise something needs to change to get better results."
