The 26-year-old Irishman, who has played for Leinster since 2006, underwent contract negotiations last year.
"I was very impressed by Rob Penney," the Irish Examiner quotes Fitzgerald as saying.
"I thought he was a really nice guy and it seemed like he had a bit of a vision for going forward. I think you can see that - they are playing pretty good stuff.
"I talked to Brian on my Dad's recommendation. Brian is a smart guy, who has managed himself really well. His advice was really surprising. He was really unbiased on why I should stay. He was really honest."
Fitzgerald is expected to start for Ireland in their opening Six Nations clash against Scotland on Sunday.