After a lengthy layoff, Fisiiahi returned on the wing for a match against the Cowboys in Townsville.
The Warriors were thrashed 30-10 - their heaviest defeat of the regular season - and Fisiiahi hasn't featured in the top grade since.
Having bulked up from 90 to 94kg, he returns bigger, stronger and, incredibly, faster. "I'm a lot faster," he told the Herald last week. "That's a compliment to [head trainer] Craig Walker and the training staff. Hopefully I get to show it."
He hasn't had to wait long to get that chance. After a strong pre-season it was his remarkable six-try performance against Western Suburbs two weeks ago that put him firmly back on the radar. Last week he followed that up with a hat-trick against Manly in a curtain-raiser at Mt Smart Stadium.
Later that evening fate again smiled on Fisiiahi, with Locke suffering the injury that would ultimately rule him out tonight.
While no one doubts Fisiiahi's ability to light up the NRL on attack, there are still questions over his defence and durability.
One club insider likened him to a high-performance car, built for speed rather than mileage.
That question over his ability to withstand heavy contact is why Fisiiahi isn't really considered a wing option. The Warriors' wingers tend to take the second carry on most sets.
With the defence set, that carry is often a brutal affair, best left to the more muscular Manu Vatuvei and Bill Tupou.
"I don't really enjoy the wing," Fisiiahi admitted. "I like running around and fullback is the position that allows me to do that. I also get a lot of opportunities running off the forwards, and I guess that is where the money is for myself."
Having been knocked around last year in his brief appearances, Fisiiahi is well aware he needs to demonstrate improved durability to survive in the top grade.
"Even playing in the New South Wales Cup is a lot more physical than the under-20s. And when you go from the NSW Cup to the top side it is another step again. The game speed changes, the physicality changes - mentally it takes a lot out of you.
"There are a lot more smarter players. You are not playing against 17- or 18-year-olds, you are playing against guys like Greg Inglis. Guys who ... are thinking two plays ahead. I guess that is what I have to prepare myself for."
There will also be interest in the form of returning prop Sam Rapira tonight as the Warriors look to get a win streak going, but it is Fisiiahi who will be under the most intense scrutiny. Big things are still expected of the club's most exciting prospect.
"With that comes a lot of pressure," he said. "You are not going to make everyone happy. I've just got to perform to the best of my ability."
Displacing the vastly improved Locke on a permanent basis is unlikely, but Fisiiahi at least has a chance to press his case.
