AC Milan chief executive Adriano Galliani said he was confident Leonardo would stay on as coach next season ahead of the third-placed team's visit to Sampdoria on Sunday.
"He has a two-year contract, I'll convince him to stay," Galliani told Friday's La Gazzetta dello Sport in response to media reports that Leonardo could take over as Brazil boss after the World Cup.
Italy midfielder Andrea Pirlo is suspended for Milan, who slipped four points behind leaders AS Roma after being held 2-2 by Catania last weekend.
Sampdoria, who are level on points with fourth-placed Palermo, will be without suspended defender Daniele Gastaldello as they look to boost their bid to secure Italy's final Champions League slot.
Brazil centre-back Juan should return from a thigh problem for Roma, who moved a point ahead of champions Inter Milan by beating Atalanta 2-1 last weekend, in Sunday's derby with Lazio.
Police had kick-off brought forward to reduce the risk of trouble.
Captain Tommaso Rocchi is vying with Argentine Mauro Zarate for a place alongside Sergio Floccari up front for Lazio, who have moved six points above the relegation zone with strong form in recent weeks.
Authorities have restricted access to second-placed Inter's home game against Juventus on Friday to season ticket holders and people with the new supporters' card, who can also buy tickets for family members, to avert trouble.
Inter defender Cristian Chivu is suspended for the game being played on Friday to give the hosts an extra day's rest before Tuesday's Champions League semi-final first leg against Barcelona.
French striker David Trezeguet is one of several players injured for sixth-placed Juventus.
