Dani Carvajal's recuperation from a pericardium infection is understood to be a matter of deep concern at a Real Madrid who are not without further injury worries. The full-back was ruled out on Saturday with the problem, which is an inflammation of the lining of the heart - and which has no definite recovery time.
Carvajal's absence has left Real boss Zinedine Zidane with a selection headache at right-back - with youth product Achraf Hakimi handed his debut at the weekend - and in the dark as to when he'll be able to call on the Spain international again.
Pericardium infection recovery time varies from patient to patient
The problem is the uncertainty. The time the inflammation takes to completely die down depends on how each patient reacts to treatment, making the recovery period difficult to estimate: it could be weeks, or even months.
Real will therefore be happy enough if he is out for three to four weeks, a stint on the sidelines that would see him miss up to seven games (including the two Champions League clashes with Tottenham Hostpur). However, it's all guesswork.
And having been prescribed complete rest by club doctors, Carvajal will have to undergo a mini-preseason to regain full fitness once given the medical all-clear.
Carvajal absence also a setback for Spain boss Lopetegui
His absence is also a blow to Spain coach Julen Lopetegui, who had included the 25-year-old in his squad for the final Group G World Cup qualifiers against Albania and Israel, but was forced to replace him - and, in all likelihood, will not have the player at his disposal in the November international break either.