Willian was a half-time substitute for Everton as Brazil beat Argentina 2-0 to advance to the final on Tuesday.
The 30-year-old however picked up a minor hamstring injury in the course of the game which will see him sit out the competition’s decider against the Peruvians.
Willian has largely featured as a substitute in the tournament but he did find the back of the net in Brazil’s 5-0 demolition of Sunday’s opponents in the last group stage game, and also converted in the penalty shootout win over Paraguay in the quarterfinals.
Willian was a last minute call-up to the Brazil squad for the Copa America, as he replaced Neymar after the Paris Saint Germain forward was ruled out on the eve of the tournament following an ankle injury he picked up against Qatar in a friendly game.
The Selecao have however strolled through to the final without the injured Neymar and are the only side yet to concede a goal in the tournament.
Brazil have not won the South American continental trophy since a 3-0 win over Argentina in 2007 but they will be hoping to break their 15-year Copa America duck on home soil when they face Peru on Sunday.
Dani Alves, who scored in that 2007 triumph over Argentina, is the only surviving member from that side and will captain Brazil on Sunday.
Peru on the other hand will be competing in their first Copa America final since 1975 after upsetting the form book to beat winners of the last two editions, Chile, 3-0 in the second semi-final.
Willian will have a new manager to work under by the time he returns to Chelsea after Frank Lampard was appointed on a three-year deal earlier on Thursday.
