Juventus coach Massimiliano Allegri has told his team that they will lose to AC Milan in Saturday's Serie A showdown at San Siro unless they improve from what he considered an untidy display in their last match.

Both teams enjoyed 4-1 wins on Wednesday with Juve beating SPAL at home and Milan winning away to Chievo, but there were very different reactions from the two coaches.

Milan's Vincenzo Montella was a happy and relieved man after his big-spending side ended a four-match winless run in the league, lifting some of the pressure off his shoulders after talk that his job was on the line.

"It's a victory that gives us belief and strength," he said. "We had already seen significant improvements in the quality of football over recent games and I am very satisfied with this performance."

There were no such sentiments from Allegri whose side rushed to a 2-0 lead in only 23 minutes but then let SPAL back into the game. The visitors pulled one goal back and had an equaliser disallowed before two quickfire goals got Juventus off the hook.

"If we play like that again, we will come away from the match on Saturday beaten and worn out," said Allegri.

"We did really well until it was 2-0 but instead of holding onto the ball, we rushed around without any sense or meaning.

"We got ourselves into a mess, and once that happens it's difficult to get back into the match again. We've taken a step back compared to the previous game. It's a real see-saw."

Former Juventus defender Leonardo Bonucci, who shocked Italian football by moving to Milan in the close season after playing a key role in six successive title-winning campaigns for the Turin side, will miss the game through suspension.