While fellow Brazilians Alexandre Pato and Kaka have been instrumental in AC Milan winning its last two league matches, the forward has been sat twiddling his thumbs on the bench.

The close season signing from Barcelona started the opening two Serie A games, which Milan lost, and failed to offer the immediate spark which the Rossoneri fans had hoped for.

But with forward Marco Borriello suffering a thigh injury after scoring the opener in Wednesday's 2-1 win at Reggina, a vacancy in the side has arisen for Sunday's game.

Coach Carlo Ancelotti believes Ronaldinho needs more time to get 100 percent fit after a tiring stint at last month's Olympics, but one of the biggest club games in the world should re-energise any weary limbs.

"I left him and Sheva (Andriy Shevchenko) out of the starting lineup only because of their physical condition. Ronaldinho will be a deciding factor for Milan when he returns to top form," Ancelotti told reporters.

Striker Shevchenko, brought back to the club after a sorry two seasons at Chelsea, will also be keen to take Borriello's place after consistently impressing in the city derby during his first seven-year stint with Milan.

The derby, however, is something new to Inter coach Jose Mourinho but the perfectionist technician is unlikely to let sentiment get in the way.

The Portuguese will add his own Brazilians into the San Siro mix with colossal defender Maicon fast becoming one of the best right backs in the world and Adriano looking more like the striker who terrorized defences before two years of problems.

Champions and league leaders Inter was pedestrian in Wednesday's 1-0 win over Lecce, in stark contrast to the flowing displays in its previous two matches.

A more passionate showing in the derby can be almost guaranteed with 80,000 screaming fans ready to create the usual electrifying atmosphere.

Last season's runners-up AS Roma has won just once this term and although some bad decisions from the officials contributed to Wednesday's 1-3 defeat at Genoa, the side is not functioning properly.

A home game with surprise high-fliers Atalanta on Sunday will be far from easy as will Juventus' trip to Sampdoria tomorrow.