TONY Miller must focus his side on league duties after the club was left reeling by an alleged betting scandal involving skipper Shaun Leaf.
Leaf is reported to have broken RFL rules by betting on Doncaster to lose their Challenge Cup tie at home to Wakefield Wildcats last weekend.
The 22-year-old, who it is alleged placed a similar bet on his own team to lose a league game in Toulouse in 2009, has been suspended pending the outcome of an investigation into the allegations.
The Dons lost 50-10 to Wakefield but Miller said: “The score didn’t reflect the manner of the performance.”
Chris Spurr (groin) and Craig Lawton (neck) are both doubtful but loan signing Dominic Dee could make his Doncaster debut after agreeing a one-month loan move from Featherstone Rovers.
Cougars coach Jason Demetriou is set to include James Haythornwaite and Brendan Rawlins, but Rick Barr (calf), Danny Lawton (hamstring) and Luke Helliwell (knee) are all facing battles to be fit.
Demetriou said: “Doncaster have been competitive in a lot of their games.
“They’ve won three, but they’ve also got two bonus points, so they’ve only had two games where they haven’t been right in it.
“It’s going to be one of our toughest game and we’ll need to be on our mettle if we want to come away with a result.”