The younger Flanagan earned his NRL debut during his father's tenure at Cronulla but only became a regular first-grader upon leaving the club for the Sydney Roosters in 2020.
By that point, Flanagan Snr had been deregistered by the NRL for remaining in contact with the Sharks while serving the ban he incurred following the club's supplements saga.
After five years away, Flanagan returns to the coaching hot seat with the Dragons next season, having last week been unveiled as Anthony Griffin's permanent successor.
Three other NRL head coaches have sons playing in the league. When Manly faced Parramatta on Saturday, there was plenty of intrigue around Jake Arthur's first match against his father, Eels boss Brad.
The younger Flanagan could be poised for his own bout against his father's Dragons if he re-signs with the Bulldogs beyond this season.
"I haven't thought too far ahead," Flanagan said after the Bulldogs' loss to Cronulla on Sunday.
"It's been a good week for the family.
"I'm very proud. I'm so happy for him.
"I imagine he was here somewhere, having a few beers, just being a dad, watching his young fella play first grade."
Flanagan has fallen out of favour at the Bulldogs in recent weeks but with Matt Burton away on State of Origin duty, played his first NRL game in two months on Sunday.
He sneaked over from dummy half for a vital try in the first half but otherwise struggled for opportunities as the Sharks forwards monstered the Bulldogs' pack in the 48-10 shellacking.
"It's a disappointing result but I'm happy to be back in the top grade," he said.
Usually a halfback at NRL level, Flanagan has switched to hooker in reserve grade to provide the Bulldogs with cover in the event of an injury to Reed Mahoney.
The 24-year-old said he had copped the switch on the chin and is aiming to approach the next chapter of his career with similar resilience.
"I've made it quite clear that I want to be in the top grade. Anything I can do to be in the top grade, I'll do it," said Flanagan, who is off-contract at the end of the season.
"I like to think I'm just a bit of a footy player and whatever number's on my back or the position I'm playing, I just go after it.
"That's sort of been my mindset the last couple of weeks and months, that whatever comes my way, just to go after it and not to worry about contracts or anything like that."
