Queensland forward Jai Arrow has suffered a syndesmosis injury in the Titans 24-20 loss to the Warriors on Friday and is set to miss the remainder of the State of Origin series.
Scans revealed the Titans and Queensland forward had suffered significant ankle ligament damage.
The Titans said on Saturday Arrow was expected miss between six and 12 weeks.
Queensland coach Kevin Walters, who was at the ground in his role as a commentator for Fox League, is due to name his team on Sunday night for the match at Perth's Optus Stadium on June 23.
As he limped from the field with the assistance of two trainers late in the first half Arrow could barely place any weight on his left leg, his contorted face a mixture of pain and disappointment.
"I'm not a doctor but I wouldn't be booking his flight [to Perth]," was Brennan's blunt assessment of Arrow's chances of playing Origin II after Friday's match.
"Jai's got the syndesmosis injury that seems to be the thing these days with ankles," Brennan said.
"I don't know the extent of it. He'll have a scan and see how it comes up but it doesn't look good at the moment that's for sure."
Tyrone Peachey will also have scans on a possible pec injury, Arrow hoping the Titans medical staff can work some kind of miracle to put him in the frame to play Game Two against the Blues.
With Joe Ofahengaue already ruled out due to the nasty gash he suffered in game one, Walters may need to find two new middle forwards.
Arrow's teammate Jarrod Wallace did his chances of a Queensland recall no harm with another wholehearted display against the Warriors.
With Kevin Proctor ruled out during the week Brennan asked Wallace to step up into a leadership role, the five-time Maroons rep responding with 181 run metres and 28 tackles in a 73-minute performance.
"He's done everything he can but it's up to Kevvie to make the call," Brennan said.
"It's the mark of a person when they have some disappointment and how they respond.
"I've seen so many players face disappointment and go the other way and kick stones but Jarrod's the exception. Anything that gets thrown at him he actually thrives on it.
"I asked him to be a bit of a leader tonight. We were down on some experience with no Kevin Proctor and then losing Jai Arrow, he was enormous Jarrod, there's no doubt about that."
Cowboys forward Coen Hess, who may have been looked at as a possible replacement in the Maroons pack, also suffered a leg injury in the golden point loss to Wests Tigers in Townsville.
Arrow's misfortune follows hard on the heels of Blues winger Nick Cotric injuring his ankle in the Raiders 22-20 win over the Sharks at GIO Stadium on Saturday.