Brisbane fullback Darius Boyd.

Broncos coach Wayne Bennett was at a loss to explain his side's dramatic drop-off in the second half of their 32-16 loss to the Storm on Sunday.

Brisbane led 12-8 at halftime and looked the more dominant team, but Bennett watched on in horror as the home side scored four tries to close out the game after the break.

"The second half, the Broncos didn't come out - I don't know where their jerseys were at," he said.

"In our first five sets, we got one set away. That's just not good. That's the last thing you need. Our intensity dropped a lot. We weren't getting off our line very well.

"Tackles weren't hitting and sticking. Everything you can name in the game, we stopped doing. I don't know what I said to them at half-time to put them in that place, but that's how they came out second half."

The loss leaves the Broncos in eighth spot.

But Bennett doesn't think it's panic stations just yet - he's just disappointed.

"I'm not going to throw the baby out with the bath water, we're doing some good things and we're still a very capable football team," he said.

"[I'm] just disappointed that we came here after a bye, won four of our last five games, came here ready to play.

"The second half leaves you a little puzzled how we can do that to ourselves. They all clocked off actually. Outside the Titans this year [in round four], it was probably the most disappointing half of football I've seen from us."

Brisbane skipper Darius Boyd, who ran for 131 metres in an energetic display from fullback, echoed his coach's comments.

"We came here with a good game plan, trained well through the week, and obviously [had] a couple of Origin boys backing up, but it was just disappointing to put in such a good half and not really turn up in the second," he said.

The Broncos did have some good moments, with interchange forward Tevita Pangai Junior running for 151 metres in his 52 minutes off the bench.

Bennett said he expects NSW centre James Roberts to be available next week against the seventh-placed Sharks.