Barcelona's Frenkie de Jong will not return to action until after the next international break at the earliest after picking up an ankle injury at the weekend, manager Xavi said.
The 26-year-old Netherlands midfielder had played every minute of Barcelona's LaLiga matches so far this season before being substituted in the first half against Celta Vigo on Saturday.
"He'll be a significant absence for us," Xavi told reporters on Monday. "Frenkie is fundamental to how we play, especially given the great form he was in.
"About the timeframe of his injury, it's going to depend on him really but we will have to assess how he's feeling after the next international break (in October)."
Barcelona visit Real Mallorca later on Tuesday, followed by a home game against Sevilla and a Champions League group stage away fixture against Porto on Oct. 4. They visit Granada in the league on Oct. 8 before the break.
Xavi said he will have to rotate his squad for upcoming matches, with midfielder Pedri also nursing a thigh injury.
"We will rotate not just for the Champions League, but also for the next LaLiga game," he added. "There will be an average of two or three players rotating every game, that's how we understand we have to prevent injuries."