Barcelona have confirmed that Maxwell will miss their La Liga title decider against Real Valladolid next weekend through injury.
The Brazil defender limped out of Saturday's 3-2 victory over Sevilla and scans have confirmed a torn leg muscle.
Maxwell has been a virtual ever-present for the Catalan club during the second half of the season in the absence of France international Eric Abidal.
He has helped them retain their one-point lead over rivals Real Madrid heading into a tense final weekend of La Liga action.
"Tests carried out on Monday morning confirmed that Brazilian defender Maxwell will be out for three weeks with a torn muscle in his right leg," read a club statement.
"The fact that Maxwell will now miss what remains of the season will come as a blow to manager Pep Guardiola, who has included the Brazilian in his last 23 consecutive squads as versatile cover for the injured Abidal.
"Maxwell's presence in attack has been particularly effective and he played a big role in the goal away to Inter or (Lionel) Messi's opening goal last Saturday against Sevilla."