The Spanish Football Federation's (RFEF) rules state that Real Madrid have just two weeks to permanently hire a new coach as they continue negotiations with Antonio Conte.
Former Spain boss Julen Lopetegui was relieved of his duties on Monday after a dismal start to the season, with the weekend's embarrassing 5-1 El Clasico loss to Barcelona the final nail in the coffin.
The 52-year-old manager was poached from the national team just before the World Cup back in June, with RFEF deciding to release him due to the announcement being made official before the tournament.
And now, following Lopetegui's sacking after having won only one of his last seven matches, Madrid must act quickly to fill the vacant position.
Goal understands that Antonio Conte is the frontrunner for the job, but his appointment is being held up due to disagreements with former club Chelsea over a compensation package.
In order to sign with Los Blancos, the Italian would have to forego a €10 million (£9m/$11m) severance, leading to the aforementioned complications.
Reserve team boss Santiago Solari has taken the reins as per Madrid's statement released on Monday, but the club will have to move quickly if they are to land their top target in Conte.
Article 160 in RFEF's General Regulations document reads:
1. If a coaching vacancy occurs after the competition (La Liga) 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.
It is worth noting that Solari possesses such a licence.
2. Failure to carry out the duties referred to in the previous paragraph will lead to the carrying out of corresponding disciplinary measures by the federation.
This being the case, Madrid have less than 15 days to make a permanent appointment as Solari's stint as the stand-in boss can last only four matches: Melilla, Valladolid, Viktoria Plzen and Celta Vigo.
The club know the clock is ticking and must either appoint Solari full time, make a breakthrough in negotiations with Conte, or simply hire another external candidate.
The Spanish capital club next take to the pitch at Estadio Álvarez Claro, where they face Melilla in the Copa del Rey.