On 21 November 2006, Kalac made his second UEFA Champions League appearance for Milan as he came off the bench in the final 15 minutes of the group match against AEK Athens. Dida tore knee ligaments and was predicted to be out for two to three months, which finally gave Kalac a chance to make more competitive appearances for Milan. Kalac's first full game in the 2006–07 season was on 25 November 2006 in Milan's 1–0 win over Messina in the Serie A.