Vlaar won great praise for his debut season in the Premier League last term.
"I'm 28 and it wasn't an easy season," admitted Vlaar. "It was my first season in the Premier League and at Aston Villa, but I could do better I think.
"I expect more from myself. When we have a new season, I think it's going to be better.
"I'm never completely satisfied with the way I play, I always look for things to improve.
"I want to be better in personal battles, I want to win more headers, I want to make less mistakes.
"I just need to be better. I think with practice you can do a lot. You train like you play so it's 100 per cent every day."