Zlatan Ibrahimovic has been ruled out of Milan's clash with Lazio, but head coach Stefano Pioli is confident fit-again Mario Mandzukic is ready to step up and fill the void.

Sweden international Ibrahimovic sat out Wednesday's 2-1 home loss to Sassuolo with a muscular problem and is not ready to return for Monday's Serie A trip to Stadio Olimpico.

The 39-year-old, who this week signed another 12-month extension with Milan, also missed the recent win against Genoa through suspension.

Rafael Leao filled in for Ibrahimovic in those two matches, but Mandzukic - a second-half substitute in both games - is in line for a first league start since joining in January after shaking off an injury issue of his own.

"Ibrahimovic is better but he won't be there tomorrow. He should be back for the following match," Pioli said at a pre-match news conference on Sunday. 

"Mandzukic and Leao will play for the place tomorrow. Mario is feeling better and has the characteristics to give himself the right contribution in the opposition box."

Former Juventus striker Mandzukic has featured seven times in total for Milan, his only start coming in the 2-2 Europa League last-32 first leg with Red Star Belgrade in February.

He has yet to score, assist or create a chance across his 119 minutes of Serie A action for the Rossoneri and has managed just three four shots, three of those on target.

Rafael Leao has played double the number of league games over that same period of time, scoring one, assisting one and creating nine chances.

The versatile Portuguese forward can play right across the frontline, but Pioli is not yet sure where he will be used in the long term.

"The Leao project continues regardless of his role," Pioli said. "It only goes to show his maturity and willingness to grow, which is normal for such a young player.

"It is difficult to establish what Rafael's final role will be. The growth of a player allows you to find a job and a position. 

"The important thing is he continues to grow and we will continue to evaluate the position along the way."

Milan have an identical league record with and without Ibrahimovic in their side this season (W10 D3 L3), and they average 1.9 goals with him in the side compared to 1.8 without.

Since rejoining the club at the start of 2020, Ibrahimovic has scored 25 goals in 35 Serie A appearances - only Luis Muriel (26), Romelu Lukaku (32), Ciro Immobile (36) and Cristiano Ronaldo (46) have found the net more often across that period.

Meanwhile, his scoring rate of 108.24 minutes per goal is bettered only by Ronaldo (88.41) and Muriel (64.42) among players to have scored at least 10 times.

"Ibra has raised the level of quality and personality, his charisma has helped everyone to grow," Pioli said following confirmation of Ibrahimovic's new contract on Saturday.

"His teammates have been good at following this path and having a growth with great constancy and will. 

"We have all grown and have become a team of a higher level. Everyone has given their contribution."