Real Madrid have two weeks to register Lopetegui's successor
It is stated so in the RFEF General Rules and Regulations. With Conte practically ruled out, Solari could take the reins on a provisional basis for a maximum of 14 days.
Once Julen Lopetegui is sacked from his coaching position, which is due to be officially announced in the next few hours, Real Madrid will name Santiago Solari as first team coach on a provisional basis. The Argentinean can remain in the post for a maximum of two weeks before the club has to register Loptegui's definitive successor with the Spanish Football Federation.
That is according to the RFEF rules and regulations, stated under Articule 60, regarding coahes and their licences:
I. If a coaching vacany occurs after the competition has started, the club will be obliged to find a new coach who is licensed for the category within a maximum time frame of two weeks.
Caretaker coach for the next four games
That means that once Lopetegui is dismissed, Real Madrid must find a permanent replacement within 14 days. The chances of Madrid bringing in Antonio Conte have become more remote as the day has wore on and barring any major surprise, the Italian won't become Madrid's new coach. RM Castilla coach Solari, who is Florentino's preferred choice for the job, will only be able to remain in charge for Madrid's forthcoming games against Melilla (31 October; Copa), Valladolid (3 November; Liga), Viktoria Plzen (7 November; Champions League) and Celta (11 November; Liga). Madrid would also need to recruit a caretaker coach to oversee Castilla's games while Solari is with the first team. After a fortnight has expired, or even before the 14-day limit is up, Solari would no longer be able to stay on in a temporary role and the club would be served a fine.