McDonald was sent off by Willie Collum for a challenge on Kenny Miller in the first half of Motherwell’s 2-0 Ladbrokes Premiership defeat on Saturday.
The Australian caught Miller on the ankle as he stretched following a heavy touch and Motherwell feel he was the victim of an injustice.
Assistant manager James McFadden said on Monday morning: “We are going to appeal the decision so Scott should be available tomorrow.
“He didn’t go in to harm Kenny Miller, he goes in to win the ball and he actually pulls out of it a wee bit. The contact happens so fast and they are so close together that we feel it was undeserved.”
Motherwell have signed winger Elliot Frear from Forest Green and loaned Reading defender Zak Jules and Everton goalkeeper Russell Griffiths in recent days. And they are still looking to do more business before the transfer window closes.
McFadden said: “There could be, we are still working away on that. But we don’t have answers back from the people we are speaking to, so we will see how it goes.”
One of those in the frame is Stephen Pearson, who has been invited back for a third spell at Fir Park following a successful spell in India. The 34-year-old is a free agent so is not bound by the transfer deadline.
McFadden said: “We have spoken to him and offered him a deal and we’re waiting to hear back. Pearo would be a great addition on and off the park here. We would love to him back so hopefully he makes the right decision and comes back.
“Being on the other side of it now, we look after our own. Having been the player who has come back three times before, I know the appeal and why you would want to come back and I know Pearo is exactly the same.
“I know he has one or two things to think about before he makes that decision but he knows he will be welcomed back with open arms here by everyone.”