Rio de Janeiro - Brazil's attacking midfielder Willian will miss Sunday's Copa America final against either champions Chile or Peru after injuring his hamstring, the tournament hosts said on Wednesday.
The 30-year-old Chelsea player was a second half substitute in Brazil's 2-0 semi-final victory over arch rivals Argentina, coming on for winger Everton.
A Brazil football federation (CBF) spokesman said Willian had felt "pain in his hamstring" and was sent for tests on Wednesday afternoon where it was found that he had a "pulled muscle."
Brazilian media said he was injured during Tuesday's match.
The CBF spokesman said the recovery time needed meant Willian would miss the final.
Eight-time Copa winners Brazil are through to their 20th final but first since last lifting the trophy in 2007 with a 3-0 victory over Argentina.
Willian had not started any of their five tournament matches so far but came on in four of them, scoring in their 5-0 group stage win over Peru and also slotting home a shoot-out penalty in the quarter-final victory against Paraguay.
He has 69 caps for Brazil, scoring nine times since making his debut in 2011.