The Irish goalkeeper moved to Villa Park for £3.5m last week after spending much of last season on the substitutes' bench at Manchester City.
The 35-year-old, who fell behind Joe Hart in the pecking order at Eastlands, admitted that he needs to be playing as regularly as possible at his age.
Given said: "For me, it's about playing football. You've got one career and I want to play as much as I can.
"I've just turned 35 and I'm at a stage in my career where I need to be playing regularly - that was all I was thinking."