Rivaldo's exclusion from the Milan squad for the Coppa Italia semi-final against Perugia sparked rumours of his discontent at San Siro.
The Italian media speculated the Samba star was unhappy at only being given a cameo role in the Milan derby on Sunday.
The enigmatic attacker featured for only ten minutes of the 1-0 victory over Internazionale and would not have been guaranteed restoration to the starting line-up against Perugia.
The rumour-mill suggested Rivaldo had snubbed coach Ancelotti's call for the cup encounter but an official statement from Milan claims the former Barcelona ace is injured.
A statement on the club website read: "The Brazilian champion worked in the gym and underwent physiotherapy after suffering a knock on his knee during Sunday's training session."
