The defender is out of contract at the end of the season and will be allowed to talk to other clubs in January.
He will not be sold in the transfer window though and Villa boss Paul Lambert, who has a strong relationship with his skipper, has spoken to Vlaar about a new contract.
But the 29-year-old is yet to sign and agent Arnold Oosterveer admits the situation is in Vlaar's favour
Oosterveer told Dutch publication Voetbal International: "It is obvious that for Ron, now is the moment to make a nice big move in his career.
"Ron is very ambitious
The situation is ideal for Ron right now.
"You can imagine that we are not in a hurry
I don't want to react to the rumour that he will go to either Arsenal or Manchester United, but Ron is very ambitious."
Vlaar has been one of Villa's best performers since signing from Feyenoord for around Â£3.2million in 2012, making 72 appearances and scoring twice.
He excelled for Holland in their run to the World Cup semi final in the summer.
Source : PA