Marrar duo Matt Parks and Damian O'Donoghue both face a race against time to play any part in the Bombers' finals campaign.
Parks and O'Donoghue were injured in Marrar's 90-point demolition of Coleambally last Saturday and have not received great news from the physio.
Parks has tore the medial ligament in his knee and will battle to be fit by the Farrer League grand final on September 14, should the Bombers make it.
Parks suffered the same injury at a similar stage of the season two years ago but returned by the preliminary final to play a part in the Bombers' drought-breaking flag.
O'Donoghue has a grade one hamstring tear and could be available come the third week of finals, should Marrar still be alive.
Marrar coach Shane Lenon is disappointed for both players.
"It's not ideal but that's footy. Injuries are apart of footy unfortunately," Lenon said.
"The boys will do their rehab and hopefully they can get back and play some part."
Parks had only been back in the Bombers senior team for a month, after seeking a clearance to North Wagga in the pre-season, and produced his best game of the year at centre-half-back against the Blues.
O'Donoghue had also showed good signs despite an injury-interrupted season.
While Marrar will lose the pair for Saturday's final round trip to Barellan, they expect to welcome four players back.
Mitch Taylor, Drew Beaven and Nick Cooper were all unavailable for the Coleambally game, while key defender Adam Whyte is expected to play his first game since suffering a thigh injury back in June.
"Obviously Whytey has got to get through training on Thursday night but it's all looking positive," Lenon said.
"He's a good backman, he's a two-time premiership player so he'll certainly be an important in."