Cristiano Ronaldo was injured after his exemplary behaviour in denying a penalty-kick in Al-Nassr's 0-0 draw against Persepolis in the AFC Champions League.
The Portuguese striker was forced off and had to be replaced by Mohammed Maran in the 78th minute due to a neck injury. His injury is a huge blow for his team as they will face their biggest rivals Al-Hilal in their next Saudi league match.
Portuguese manager Luis Castro assured at Monday's press conference that they will try to get the 38-year-old back to full fitness as soon as possible for one of the most important games of the season.
The Saudi side booked their ticket to the next round of the AFC Champions League with Monday's goalless draw. As a result, they are focused on their next match against Al-Hilal and will be looking for Ronaldo to be able to help his team.