AC Milan manager Massimiliano Allegri had no complaints at referee Nicola Rizzoli's decision to send striker Zlatan Ibrahimovic off in Sunday's goalless draw with Napoli.

Juve, Milan held; Inter thrashed

Milan failed to take advantage of leaders Juventus' goalless draw with Siena as they were held to the same scoreline against Napoli at the San Siro in a match where Ibrahimovic saw red for slapping opponent Salvatore Aronica near the hour mark.

The Sweden international was angered by Aronica placing his right arm around the back of Milan team-mate Antonio Nocerino and moved to slap the player for his troubles.

After the game, Allegri admitted the referee had little choice but to send his star striker off, but also stressed that his team has the strength in depth to deal with Ibrahimovic's resulting suspension.

"I am pleased with [referee Nicola] Rizzoli," Allegri told Sky Sport Italia.

"I had not seen anything at the time, but after watching it on TV Ibra deserved to be sent off.

"I am not worried about his absence, regardless of the fact that he is a key player for us."

With Milan at a numerical disadvantage for the last third of the game, Allegri revealed that he was satisfied with his side's display as well as the outcome of Sunday's Serie A clash.

"It was important to turn in a good display against a team that was able to cause us problems," he explained.

"Then we were reduced to 10 men, but we did not stop playing. This point has allowed us to recover the spirit that we must have to target the Scudetto.

"Of course that we have to improve in certain situations, but we did not run many risks, even when we were a man down."

Napoli are still waiting for their first win in five games.