Real are five points behind Barca in second place at the halfway stage of the season and, with Gonzalo Higuain injured, Kaka misfiring and Karim Benzema out of sorts, Ronaldo is more important than ever to their campaign.
Real have said that if their appeal to the Spanish football federation (RFEF) is unsuccessful they will take the case to Spain's Sporting Disciplinary Committee (CEDD), a body overseen by the government sports council (CSD).
That could mean the suspension is put on hold and the Portuguese forward would then be available to coach Manuel Pellegrini for the match in Coruna.
"He's a key player who brings a huge amount to the team," defender Sergio Ramos said at a news conference on Wednesday.
"But Real Madrid can't allow themselves to be affected by this," he added. "Our squad has a lot of depth and I am sure other players will make the most of their chance."
Opinion is deeply divided in Spain over whether Ronaldo was guilty of dangerous play or even deliberate aggression when he caught Malaga defender Patrick Mtiliga with a flailing arm and broke his nose.
The RFEF's disciplinary committee decided his actions were not wilful or reckless, which would have meant a longer suspension, but that he had been guilty of dangerous play.
"We all think the same," Ramos said. "We believe Cristiano did not mean to injure the player and the punishment is unfair. These are involuntary actions without any malice."
Undefeated champions Barca can stretch their lead to eight points with a win at mid-table Sporting Gijon earlier on Saturday and coach Pep Guardiola should have Yaya Toure available after the Ivory Coast midfielder's return from the African Nations Cup.
Club captain Xavi has warned his team mates against complacency.
"There is a lot of time left in the season and Madrid will battle until the end," he told reporters.
"We cannot afford to relax but we have the good fortune that we only have to focus on ourselves."
Valencia, five points behind Real in third, play at sixth-placed Sevilla on Sunday.
