The presence of Cristiano Ronaldo and Sadio Mane in the Al Nassr team I think is one of the major reasons they're being considered a strong contender for the trophies in Saudi Arabia. Apart from the fact that they're known global superstars, they also help bring their leadership qualities to the team thereby improving the mentality of the other members of the squad.
Since he signed for Al Nassr, no player have scored more goals for any Saudi Pro League club than Cristiano Ronaldo have managed so it's safe to say that he's the most influential footballer in the Saudi Pro League in the last three seasons so yes, Al Nassr will definitely suffer without the presence of Cristiano Ronaldo and Sadio Mane.
Actually, the difficulties that will be experienced are also related to the developments experienced by other teams in the Saudi Pro League. Ronaldo and Mane helped Al Nassr in catching up with the gap they experienced with strong teams such as Al Hilal and Al Ittihad.
The presence of Ronaldo and Mane is also an ambition to win the league, but so far they have not been able to get it. So they have to use a bigger way to be able to defeat the dominance of Al Hilal and Al Ittihad.
If he can finish it easily, it will not hurt anyone and it will keep the Saudi League running smoothly. Even so, if someone can get hurt, it will be only our opinion, but if something like this happens, it will reduce the points of the teams, but it will not harm the league. Ronaldo and Mane are very good and powerful players but they are not winning the league due to pressure and hard work of other players. If they had such a way, they would definitely use it, whatever they thought of it.