Neither side could find the net in the Milan derby, while Roma missed the chance to go second.
Napoli are within five points of Roma and a Champions League place after a comfortable 3-0 Serie A victory at Cagliari.
Genoa left Cagliari even deeper in relegation danger with a 2-0 win at the Stadio Luigi Ferraris on Saturday.
Lazio kept the heat on second-place Roma by clinching a seventh consecutive Serie A success, 3-1 at 10-man Cagliari.
Juventus closed in on a fourth straight Serie A title after a 2-0 victory over Empoli.
Roma midfielder Radja Nainggolan is unsure whether he will remain with the Italian club next season.
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