Barcelona have confirmed that Luis Suarez will be sidelined for the next month but hope to have Gerard Pique available for Sunday's La Liga curtain-raiser against Real Betis at Camp Nou.
Both players ended Wednesday's Spanish Super Cup defeat to Real Madrid with knocks, and tests at the club's training ground on Thursday confirmed the extent of Suarez's knee problem.
It was better news for Pique, who isn't expected to be out of action for too long, if at all.
"Luis Suarez will be out of action for around four weeks," the Catalan club said in a statement. "Tests carried out on Thursday confirmed that the Uruguayan has a distension in the posterior articular capsule in his right knee picked up in the second half of Wednesday's Clasico at the Santiago Bernabeu.
"Further tests carried out on Gerard Pique confirmed that the defender has a groin strain in his left leg and his recovery will dictate his availability for the game against Betis."
Suarez will miss Barca's league matches against Betis, Alaves and Espanyol and possibly the trip to Getafe later in September.
Uruguay had earlier confirmed the striker's absence for "four to five weeks," ruling him out of his country's important World Cup qualifiers against Argentina on Aug. 31 and Paraguay on Sept. 5.
It comes at a time when Barcelona are short of forward players, with Sergio Busquets calling for attacking reinforcements earlier this week and the club openly admitting they are trying to sign Borussia Dortmund's Ousmane Dembele and Liverpool's Philippe Coutinho.
In the meantime, Paco Alcacer, a €30 million signing last summer, is likely to take Suarez's place in the team.
Barca also have fitness concerns over Andres Iniesta and Thomas Vermaelen going into the opening round of La Liga fixtures this weekend.
Iniesta has not trained this week due to a thigh problem and missed the loss to Madrid. Vermaelen hasn't featured since picking up a knee injury in a preseason friendly against Gimnastic.