Lille are reported to have made the first signings of Marcelo Bielsa's reign, with Sao Paulo duo Luiz Araujo and Thiago Mendes joining the Ligue 1 club.
ESPN Brasil and Globo Esporte reported the players would cost a combined €18 million as Bielsa, appointed on a two-year deal last month, bids to improve on Lille's 11th-placed finish last season.
Luiz, a 20-year-old striker who recently signed a contract extension until 2021, had already been approached by Lille during the January transfer window.
Midfielder Thiago, 25, is also under contract until 2021 and has just returned from a lengthy layoff caused by a knee injury.