Barcelona's French defender Eric Abidal underwent surgery "without incident" on Thursday to remove a liver tumour, the Spanish club said.
"Depending on how he evolves, the player may be discharged from hospital in approximately one week," it said in a statement posted on its website.
The defender, who signed from Lyon in 2007, played in both legs of Barcelona's Champions League last 16 defeat of Arsenal, the second leg held just earlier this month.
Abidal has been capped 52 times for France, having made his debut for his country in 2004.
He has played in two World Cups, helping France reach the final in 2006, as well as Euro 2008.