Maicon Pereira de Oliveira, a 25-year-old striker at Ukrainian football club Shakhtar Donetsk, died in a car accident early on Saturday, the club has announced.
A statement on the Shakhtar Donetsk website said the player was killed in a car accident in the city. No further details of the crash have been revealed.
"FC Shakhtar regretfully informs that on 8 February 2014 the life of a footballer Maicon Pereira de Oliveira tragically ended. He died in a car crash in Donetsk.
"He was a talented footballer, open and friendly guy. Maicon loved life and knew how to make it positive and bright. Tragic, untimely and absurd death took away a wonderful person from our ranks. Maicon was only 25 years old.
"It is a terrible bereavement for each of us. FC Shakhtar expresses condolences and sympathy to Maicon's family and friends. May he rest in peace."
The Brazilian joined the Ukrainian team in the summer of 2012 on a three-year deal. He made six appearances, scoring one goal. Maicon was on loan at the Ukrainian league club and top-flight rivals Illichivets Mariupol until the end of the 2013-14 season.
Chelsea start Willian, a former team-mate of Maicon at Shakhtar Donetsk, posted on Instagram: "Rest in Peace, God comfort the whole family, so sad."
Football fans reacted with shock on other social media sites. Jay Williams tweeted: "Horrible news about Maicon that. Some player he was. RIP."
Ciaran McCourt said: "RIP Maicon... few months before the World Cup being hosted in his home country too - would have been a great asset to brazil team #tragic."