Barcelona full-back Dani Alves could be out for up to a month with a groin strain he suffered during Sunday's La Liga win over Athletic Bilbao.
The 32-year-old was replaced 19 minutes into Barca's 1-0 win at San Mames after clashing with Bilbao's Aritz Aduriz.
Barca did not say how long Alves might be sidelined, although Spanish media reported it could be up to four weeks.
The club also revealed the ankle injury suffered by Sergio Busquets in the same game was "nothing important".
The 27-year-old midfielder was replaced by Marc Bartra in the second half in Bilbao after a collision with Athletic striker Aduriz.
The champions will hope to have Spaniard Busquets available for Saturday's La Liga game against Malaga at the Nou Camp.
If the worst prognosis of Alves' injury proves correct, he will also miss a further three league fixtures: away at Atletico Madrid on 12 September, at home to Levante on 20 September and the trip to Celta Vigo three days later.