The 27-year-old first suffered a cruciate knee ligament injury in September 2007 while playing for Feyenoord, the resulting surgery keeping him out for the entire 2007/08 season.
Twelve months later and after battling his way back to fitness, the Netherlands international suffered the same injury during pre-season training, causing him again to sit out the entire campaign.
Thankfully for Vlaar he was able to regain his fitness and form, with his displays at the heart of the Feyenoord defence catching the eye of new Aston Villa boss Paul Lambert, who moved quickly last July to bring him to the Premier League.
He has been a mainstay in the Villa defence since, missing just one game - against Tranmere in the Capital One Cup last August.
He admits that his battles with injury have ultimately made him a better player, adding a steel and determination to his footballing talents.
"I was just happy to play again but, as a top athlete, that's actually not enough," he said. "I came from a dark side and I was wondering what level I could get to.
"I'm a fighter. When I started my recovery it was just looking forward and the light at the end of the tunnel became bigger and bigger."
He added: "The doctors didn't say something like it could end my career because that's not very helpful in your mind.
"After the second time it was hard until the surgery. Then one way - up."
Villa take on Manchester United at Villa Park on Saturday and Vlaar admits games such as that are why players make the move to the Premier League.
However, thanks to his injury-plagued past he insists he takes every game seriously, regardless of the opposition, as he knows he is fortunate to be playing at all.
When asked whether he will raise his game for the Red Devils, he added: "No. I try to play as good as I can every game.
"Against bigger clubs you are motivated you mean? That is bad, you have to be the same every day.
"I am a player who likes to win every fight, every game. I am looking forward to playing against strikers I have not played against before."