The Nashville Predators, Toronto Maple Leafs and Dallas Stars have also expressed an interest in the London, Ontario native.
Gagner was limited to 67 games this season due to ankle issues and a broken jaw. He collected 10 goals and 27 assists for 37 points.
The Oilers were initially believed to be asking for a young defenseman and a draft pick in exchange for Gagner. It's unclear if their demands have changed.
Drafted sixth-overall by the Oilers in the 2007 NHL Entry Draft, Gagner has two-years left on his contract. His salary is $5 million, per year, over the next two seasons, though his annual salary cap hit is $4.8 million.