Dugan, who had previously been in the bad books for breaching COVID rules in June, was pulled over by police in Lithgow, 150km away from his home in Sydney on Friday night.
"The thing about Josh Dugan is he's now 31 years of age and off contract," Gallen exclaimed on Monday night.
"Unfortunately throughout his career, he's had minor issues, nothing too bad, but minor issues.
"I think Josh has played his last game in the NRL. I think his next move will be Super League or retirement."
Earlier in the year a report from The Hull Daily Mail claimed that Dugan was a name being floated around regarding a switch to the Super League.
With this most recent breach it seems that the only option for Dugan should he wish to continue playing lies in England, with Cronulla seemingly not willing to front up with a new contract.
Cronulla will be hoping to put these off-field issues aside and secure a finals berth over the last two weeks of the year.
This week's penultimate round of home-and-away football sees the Sharks 'welcome' the Broncos to Suncorp Stadium, with a win here pivotal considering their match against the top of the table Storm in Round 25.