Xavi admits Barcelona's players are shocked by the club's 12-month transfer ban.
Barca have announced they will appeal against the ruling.
Xavi said: "In the dressing room, and the Club, we believe that the sanction is disproportionate and unfair. The Masia does everything perfectly correctly and we'll try to defend it to the maximum. We hope that it all comes to nothing.
"We've suffered so many blows this season but we still feel strong and competitive. These things unite the team."