Brisbane's bench was outplayed and outmuscled by Cronulla in their 22-12 loss and a solution will be vital to the club's finals chances.
The Sharks had runaway train Royce Hunt and dynamic duo Jack Williams and Thomas Hazelton come on to provide ferocity and momentum in Saturday night's win at Suncorp Stadium.
The same could not be said for Brisbane trio Fletcher Baker, Jack Gosiewski and Kobe Hetherington.
In six runs, Hunt made 88m and had six tackle busts, twice as many busts as the Broncos trio combined.
The other member of the Broncos bench - hooker Tyson Smoothy - was solid and scored a try but does not strike fear in the opposition.
Broncos skipper Patrick Carrigan played 70 minutes after backing up from State of Origin for Queensland. He topped the tackle count with 48 and ran for 153m in a powerhouse display. He lacked help.
The Broncos led 12-4 at halftime but capitulated in what Walters described as the side's "worst half of football" of the season.
Starting prop Payne Haas, also backing up after playing with NSW in Origin, and fellow front-rower Corey Jensen were off the field when the Sharks launched their second-half comeback.
"You can't question Patty's commitment," Walters said.
"That is who I feel sorry for ... and Payne. Payne's commitment was really good ... but the guys that didn't play (Origin) didn't support the ones that did.
"Our first set in the second half was poor with the ball and it just got worse from there. We will have to look at everything that we are doing,."
Walters was pressed on his lacklustre bench but was reluctant to single out individuals publicly.
'I didn't see it that way but the video never lies. I'll have a look at it again but our errors cost us in the second half," he quipped.
Quizzed again on the lacklustre bench. Walters said he didn't like to be "too critical after a game".
"I'll have a look at it and I will get back to you," he said.
The Broncos will get tyro bench forward Xavier Willison back next week against South Sydney on Friday night.
"He and his partner had a baby during the week. He couldn't get to training so we thought it was best he spend time with his family and come in next week and get ready for Souths," Walters said.
During the Origin period, in particular, the quality of the bench can be make or break but Walters said the solution to the Sharks loss was about cutting out errors and poor decision-making.
The Broncos have now lost six games out of 13, the same number as they lost for the entire 2023 season.
The bench is far from Brisbane's only concern. Halves Ezra Mam and Jock Madden's last play options failed to hit the mark. The Broncos are missing injured skipper Adam Reynolds who is not expected back until the closing rounds of the season.
