Staggs trained with the reserves on Tuesday but will miss Friday night's clash at Suncorp Stadium to attend a funeral of a close friend in NSW.
Oates, who trained on the left wing, returns to the starting line-up after missing two games with a knee injury.
Deine Mariner moves from wing to centre to cover the loss of Staggs.
The omission of Staggs is a blow to the Broncos who have lost four games in a row and have just seven middle and edge forwards available in their top-30 squad after prop Fletcher Baker (MCL) and second-rower Jack Gosiewski (broken arm) were both injured in the 32-16 loss to the Warriors.
Dallin Watene-Zelezniak crashes over for a Warriors try against Brisbane. (Andrew Cornaga/AAP PHOTOS)
Brisbane have named Kobe Hetherington in the second row to partner Brendan Piakura.
Queensland lock Pat Carrigan trained for a portion of Tuesday's session as an edge forward while Hetherington spent time with the reserves in a red no-contact bib due to the extra minutes he played against the Warriors.
It is expected that Carrigan will play in the middle but switch to an edge when Hetherington needs a break.
Carrigan, prop Payne Haas and fullback Reece Walsh all return from State of Origin duty after missing the trip to Auckland.
The Broncos will carry an outside back on the bench with Josiah Karapani edging out Tristan Sailor for the role.
Winger Jesse Arthars, who missed six matches with a broken jaw before returning last weekend, said Staggs would be missed but acknowledged injury had been a constant in Brisbane's season.
"When I was sitting on the sidelines there were a few injuries happening and that is one frustrating thing when you can't get out there," Arthars said.
"For me to be available this week it is going to help. Not having Tones there, I am glad to be back to be able to contribute to hopefully a win."
The Broncos have slipped to 10th on the ladder but Arthars said the mood around the club was far from sour.
He said coach Kevin Walters was driving a belief that they could still challenge for the title.
"When you go through a couple of losses like we have it is not always easy but the number one thing for Kev is pushing positivity," Arthars said.
"Kevvie is a winner and has demonstrated that when he used to play. With his leadership as a coach we will go a long way."
10°C