Barcelona have found it hard to agree new contracts with several key players, according to a report.
The club have been struggling financially in recent months, making their position difficult in contract negotiations with players whose current deals run out next summer.
However, according to Marca, contract talks have stalled in the last few weeks, meaning the club risk losing the trio for nothing.
Last month, president Joan Laporta said "the renewal of Sergi Roberto has been agreed and the only thing missing is the signature", but no announcement has followed.
Meanwhile, Fati is seen as Barcelona's greatest source of hope for the future, but his agent Jorge Mendes will aim to negotiate the best possible deal for his client as he knows how valuable the teenager is to the club.