“Another year (would be ideal),” he told Australian media.
“I know I’m getting on in age but this is the first time I’ve done a pre-season before Christmas since 2007 – it’s been a really long time because of the tours I’ve been on.
“Physically I’m still right up there in terms of strength and fitness, so I’m not falling behind in areas there and still training really good and I still really love the sport.
“I think one more year and then I’ve always said I wouldn’t mind going overseas.”
Gallen started talks last year about an extension to his playing deal beyond 2015, but CEO Steve Noyce left the troubled Sharks.
Gallen is reportedly keen to begin talks with Noyce’s successor Lyall Gorman about extending his career with Cronulla.