Head coach Gary Thornton admitted the Dons’ Challenge Cup defeat at Hunslet Hawks was a tough watch.
Joe Pickets-O’Donnell was sent off in a 48-6 reverse at the John Charles Stadium on Friday night.
Mike Kelly, Kyle Kesik, George Milton and Sam Doherty also picked up injuries and are likely to miss this Friday’s League One clash at home to York City Knights.
“It was tough watching the second half and an uncomfortable evening all around,” Thornton told the club’s official website.
“But fair play to Hunslet, they showed a lot of enthusiasm where we lacked a lot of enthusiasm and deserved the win.
“I hope we learn lessons from that because it was simply not good enough and I’m very disappointed throughout.
“We are back here in five weeks time and I am sure we will come back in a better state and put up a better performance. I expect us to win the league game. The league is our priority but that doesn’t take away from the disappointment.
“We need to take a long hard look at the video and some of our players need to have a look at themselves.”
Liam Welham said: “The red card didn’t help but if I’m brutally honest I don’t think it would have changed the outcome.
“We didn’t turn up. It is a massive wake up call.”