The ever-confident Fifita, who was last year named in the emerging Blues squad used to identify future Origin players, has a long-held desire to break into the game's toughest arena.
And after Fifita's second pre-season at the Sharks, Flanagan is predicting big things from the 120kg powerhouse.
"He's had a year with us now and he's just looking a picture," Flanagan told AAP.
"He's gone from being that No.14-17 player to being a guy who is going to start a lot of the time.
"He's really developed into a good young front rower now. Everyone evolves and he's definitely come along in leaps and bounds."
Whether that translates into a call-up to Laurie Daley's squad for this year's State of Origin series is another matter, but the front row has been a problem area for the Blues during Queensland's record-breaking seven-year dominance.
NSW have called upon 12 front-rowers in the past three series compared to just six from Queensland, who have been boosted by reliable Australian trio Petero Civoniceva, Matt Scott and Ben Hannant.
In contrast the most successful Blues option has been Sharks and NSW skipper Paul Gallen who moved from lock to prop to great effect.
Flanagan said Fifita had the attitude and ability to wreak havoc at any level.
"He's definitely a confident kid. He backs his own ability and the challenges we put in front of him," Flanagan said.
"He's 120 kilos and he's very, very mobile for a big bloke.
"He's got some work to do because Origin is another step, but he's heading in the right direction.
"If he nails down a starting spot for us that's definitely another move in the right direction.
"If he gets that down pat then who knows? He could be talked about in rep footy times."
Flanagan said Fifita had been guilty of trying to do too much at times last year, but has matured under the leadership of Gallen and former Maroons prop Ben Ross.
"(He has improved in) just general maturity to the game and understanding what his role is within the team," Flanagan said.
"(Last year) he was probably trying to do too much at different stages and wasn't focused on what he had to do for the team.
"He's an explosive type of player, he's got some good skill and he's a big man.
"It's just taken a little bit of time for him to understand where he fits and what the game is about.
"But the penny is starting to drop there for him."