Gremio chief André Krieger admits an Italian agent holds the transfer rights of fullback Felipe Mattioni, but is adamant he won't leave until their Copa Libertadores campaign is over.

Krieger explained: "The transfer rights of Felipe Mattioni were sold (to agent Mino Raiola), I confess that I do not know the details but they were sold.

"The player, however, remains with Gremio, at least until the next Copa Libertadores."

The problem for Gremio is that any decision over Mattioni now rests with Raiola, who has held talks with Juventus about a January move for the defender.