With the Red Devils unwilling to commit to the reported R90-million valuation for the 29-year-old Uruguayan playmaker, Mosimane suggested they will now look elsewhere.
"What are we going to do? This is the current situation and regarding new signings, we may or may not need. Sometimes you look for something and you find it in your home," he said.
Mosimane further explained the form of Mohamed Sherif, who returned alongside Ahmed Yasser Rayyan from fruitful loans in the 2019/20 season, has offered him plenty of new options in attack.
"Mohamed Sharif is playing the role that we are looking for and we will give him our full confidence, and there will be a competition with Marwan [Mohsen] and Ahmed Yasser Rayyan," he explained.
"If we find a player with special abilities before the Club World Cup, why won't we sign him? We need two players with special characteristics."
The two-time CAF Champions League-winning manager returned to the dugout on Monday evening with a 4-0 win over Al Ittihad after a two-week layoff due to the contraction of Covid-19.