Barcelona forward Luis Suarez picked up a hamstring strain in Tuesday's Champions League match at Bayern Munich and will undergo a course of physiotherapy, the La Liga leaders said on Thursday.
The Uruguay striker, whose form since the turn of the year has helped propel Barca to the brink of a treble of Champions League and Spanish league and Cup titles, could miss Sunday's La Liga game at Atletico Madrid if he does not recover in time.
Barca, four points clear of second-placed Real Madrid with two matches left, can make sure of a fifth La Liga title in seven years with a win at last season's champions.
They went through to next month's Champions League final 5-3 on aggregate despite losing the semi-final, second leg 3-2 at Bayern and will play Athletic Bilbao in the King's Cup final at the end of this month.
"Luis Suarez, with a hamstring strain in his left leg, will have physiotherapy and the progress of his recovery will determine when he can train again," Barca said on their website.
Suarez, who joined from Liverpool in July, has scored 24 goals in all competitions since his ban for biting an opponent at last year's World Cup finals expired at the end of October and has also made 16 assists.
