The Brazilian is currently on international duty in the Confederations' Cup in Saudi Arabia and will be absent from Serie A for the first time this season. Marco Branca will probably replace Ronaldo alongside the Frenchman Youri Djorkaeff.
Other options, such as Uruguayan Alvaro Recoba, the Chilean Ivan Zamorano or Maurizio Ganz, are ruled out for a variety of reasons. Recoba is also at the Confederations' Cup, Zamorano is still recovering from injury and Ganz is involved in a possible transfer deal with local rivals Milan.
Inter will also be without injured Dutch midfielder Aron Winter, but have a strong midfield with Argentinians Javier Zanetti and Diego Simeone along with the Brazilian Ze Elias and ex-Roma player Francesco Moriero.
Despite the absence of Ronaldo and others, Inter come into the game in buoyant mood following an impressive Uefa Cup quarter-final qualification with a 3-0 midweek win against French side Strasbourg.
Visitors Roma are also confident after one of their best league starts in the last decade.
Easy 3-0 winners against Atalanta last Sunday, Roma are currently joint third with on 22 points, five points behind the leaders, Inter.
They, too, will be without key players in Brazilian defenders Aldair and Cafu as well as midfielder Luigi Di Biagio. The Brazilians are on international duty while Di Biagio is suspended.
Either Spanish midfielder Ivan Helguera or Damiano Tomassi replaces Di Biagio with Matteo Pivotto and Filippo Dal Moro coming into defence.
Roma will field their impressive attacking trio of the Argentinian Abel Balbo, the Brazilian Paulo Sergio and Francesco Totti. Balbo, scorer of 104 Serie A goals, is sure that his side is strong enough to compensate for the absentees.
Second-placed Juventus, who trail Inter by two points, are in high spirits after qualifying for the European Cup quarter-finals and visit struggling Piacenza. Udinese, in fourth place behind Roma on goal difference, travel to Bari.Reuse content