Gallen, 37, has confirmed he will play on for a record 19th and final season in the NRL next year.

While the decision was in Gallen's hands as he closes in on Andrew Ettingshausen's games record at the Sharks, Flanagan spoke to Bellamy about how he's dealt with his Storm veterans.

Premiership heroes Billy Slater and Ryan Hoffman are bowing out of Melbourne at the end of the season, while captain Cameron Smith is likely to play on.

"I think last week proved to me and a lot of other people that (Gallen's) still playing good football," Flanagan told reporters on Friday.

"(Bellamy) probably agreed that Gal's playing good football and we'd be crazy to not encourage him to continue to play."

Flanagan laughed off suggestions Gallen could play into the 2020 season, declaring next year is "100 per cent" his final campaign.

"I think Gal really appreciates that he does have an end date now...next year is his last year and he'll approach it like that," Flanagan said.

Gallen says a recent chat with Slater and retiring teammate Luke Lewis convinced him to go around again, realising he was was different to the pair.

"I just enjoy competing and I know I'm not going to be able to do it forever," he told The Nine Network's Footy Show on Thursday.

"Billy said he doesn't want to empty the tank but I went away thinking 'I do, that's me'."

"I do enjoy having a go at everything. I know I am not going to be the best at everything but I am going to have a crack at everything."

With another retiring great Johnathan Thurston having a sometimes difficult year at a struggling North Queensland after playing on in 2018, Gallen conceded he may not be writing a fairytale script.

"I'd rather retire regretting having a go then not having a go and having that thought 'what if I had played that extra year," he said.

"That has sort have been my whole thought process behind it."

Australian Associated Press