Holmes is set to roll the dice in a bid to play on Saturday after being charged with a grade-two careless high tackle following last weekend's loss to the Gold Coast.
The Australian international is believed to be seeking a downgrade to a fine which would ensure he can play against the Broncos, but if he loses he risks incurring an extra game's suspension.
It's a big risk for the Cowboys, who sit just inside the top eight, as they bid to continue their late-season resurgence and return to the finals.
Forward duo Heilum Luki and Griffin Neame return for the Cowboys as the Broncos welcome back winger Jesse Arthars.
St George Illawarra forward Jack de Belin is also contesting a hip-drop tackle charge and will be free to face Parramatta on Sunday if he is cleared.
Five-eighth Dylan Brown is available for the Eels after serving a suspension for groping a woman in a Sydney nightclub.
Elsewhere, Melbourne have man mountain Nelson Asofa-Solomona (finger) fit for their trip to Penrith on Friday as the Panthers name Zac Hosking in the centres.
Hosking is filling in for Tyrone Peachey (suspension) although Izack Tago is part of the Panthers' extended squad and could slot into the centres if given the green light.
Storm fullback Ryan Papenhuyzen is due to make his comeback game in the Queensland Cup nearly 13 months after fracturing his kneecap.
Canberra, meanwhile, have dropped hooker Tom Starling from the interchange bench for rookie Adrian Trevilyan for Sunday's meeting with the Wests Tigers.
Winger Nick Cotric comes in for Jarrod Croker (hamstring) with Seb Kris moving to centre and Jordan Rapana assuming fullback duties.
As part of Saturday's double header in Perth, an unchanged Newcastle side face the Dolphins with Cronulla naming Connor Tracey at fullback for their meeting with South Sydney.
In Friday's early kick-off, Jazz Tevaga is in line for his first game since April as the Warriors face the Gold Coast, whose fullback AJ Brimson has been cleared of a rib injury and will be good to go.
