Henjak named 18-year-old Corey Norman in injured skipper Darren Lockyer's No.6 playmaking role against the Eels but started with the more physical Gillett, who looked out of sync at times in attack.
While he got through 24 tackles, the third best defensive workload on the night, he wasn't as sharp with the ball in hand.
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Few, if any, players can deliver the ball to their strike weapons quite like Lockyer, who's looking at sitting out at least another game, perhaps even two, with a painful rib cartilage injury that is causing the club's medical staff some concern.
Opinions were divided on the Gillett experiment but Henjak seemed satisfied enough to suggest he could give him another crack against Newcastle next Friday night.
Gillett, in the running for NRL rookie-of-the-year, has played multiple positions in his debut season, scoring 11 tries.
"We'll revisit it, but I thought Gillo went alright there actually ... I don't that was the reason (we lost)," said Henjak.
"I'll have another look at it, but I thought he had a really good game."
Norman was guilty of a defensive lapse in the second half when halfback Kris Keating fooled him with a change of pace to set up a try for centre Joel Reddy.
Henjak said Brisbane, who could find themselves out of the top eight by the end of the weekend, would not be looking at equations to make their 19th straight finals.
"For some teams, and for us too, but especially for the teams below us that are fighting for the top eight, it is finals football already," said Henjak.
"They're finals-type games out there and the pressure is on and they're playing for their lives. I'm not sure if one win (from the remaining three games) is going to be enough.
"I'd rather get two. Whatever the equation, we're not worrying about three games now. We just need to get our next one out of the way.
"I don't want to start looking at equations and hoping someone beats someone else, and all that sort of stuff. Hopefully we're still in the eight (at the end of the weekend) and it's still in our own hands."
While Brisbane missed Lockyer's composure against the desperate Eels, Henjak dismissed rushing him back from his rib cartilage injury too soon.
"We're not going to bring him back if he's in pain, or if he's hurt and can't function properly," he said.
"It would be handy to have Locky there, but the reality is he's not and we have to get on with life.
"We can play better than that and we need to ... everyone has to step up to the plate."
