Juventus are determined to show better form this weekend with their old nemesis coming to Turin. Zdenek Zeman, meanwhile, would like nothing more than to end Juve’s 44-match unbeaten streak in the Italian league.

Tuesday’s 0-0 draw at Fiorentina was Juve’s worst performance of the season and now the Bianconeri host an unpredictable Roma squad coached by Zeman, whose accusations 14 years ago led to a disturbing doping investigation into Juventus.

Also this weekend, striving Napoli visit nearly as impressive Sampdoria; AC Milan play Parma and Inter host Fiorentina at the San Siro.

Juve and Napoli share the lead with 13 points each. Sampdoria are three points behind despite a one-point penalty from a betting scandal, while Inter and Lazio are four points behind.

Juventus were thoroughly outplayed by Fiorentina and was fortunate to come away with a draw Tuesday, ending the club’s perfect start to the Serie A season.

Juve went all of last season undefeated in the Italian league. It’s tough to imagine a repeat this campaign with the added challenge of the Champions League.

Juve opened the Champions League with a 2-2 draw at defending champions Chelsea last week and will host Shakhtar Donetsk on Tuesday for their first home match in the top club competition in three years.

Against Fiorentina, midfield maestro Andrea Pirlo was subjected to a rare coaches’ choice substitution, with the 33-year-old struggling to maintain his form. His replacement midway through the second half was 19-year-old French player Paul Pogba.

“We have to find a way to let Pirlo train more. By playing every three days he doesn’t have any time to train and that’s affecting him,” said interim Juventus coach Massimo Carrera, who is filling in while Antonio Conte serves a 10-month touchline ban for match-fixing violations stemming from when he coached Siena two seasons ago.

Diminutive forward Sebastian Giovinco is also struggling, with Mirko Vucinic the team’s only consistent performer in attack.

Still, the Turin club isn’t panicking.

“Juve continue to not lose and that’s a sign of strength,” Carrera said.

Pointed accusations over Juve’s strength back in 1998 by Zeman — during his first stint as Roma coach — led to a trial spearheaded by Turin anti-doping prosecutor Raffaele Guariniello.

In 2004, Juventus physician Riccardo Agricola was convicted of administering banned substances, including the hormone EPO, to Juventus players from 1994-98, and was handed a suspended sentence of 22 months. He was cleared on appeal a year later.

Retired Juventus players Gianluca Vialli and Ciro Ferrara continue to trade verbal jabs with the Czech coach, as was seen earlier this week ahead of Roma’s 1-1 draw with 10-man Sampdoria, who are managed by Ferrara.

While little has been said about the Juve-Roma match, earlier this season Zeman questioned how Conte is still allowed to train his squad during his touchline ban.

Before signing with Roma this season, Zeman had not coached in Serie A for seven seasons. He led Pescara to the Serie B title last season.

Roma showed their potential with a 3-1 win at Inter in the second week of the season but has struggled lately, giving up a two-goal lead in a 3-2 defeat to Bologna, then allowing 10-man Sampdoria to equalize on Wednesday.

Francesco Totti, Roma’s 36-year-old captain, scored his first goal of the season against Sampdoria, while recent Italy call-up Mattia Destro is still struggling to find the target.

Napoli are coming off a 3-0 win over Lazio, with Edinson Cavani having scored his sixth hat trick in Italy. The southern squad progressed to the Champions League knockout round last season and seems likely to improve on their fifth-place result in Serie A.

Both Milan clubs are also showing signs of improvement following difficult starts.

Milan beat 10-man Cagliari 2-0 with two goals from 19-year-old Stephen El Shaarawy on Wednesday for its first home win of the season, while Inter won 2-0 at Chievo Verona.

With Massimiliano Allegri suspended, assistant coach Mauro Tassotti guided Milan amid reports that he could be a possible replacement for Allegri, who led the Rossoneri to just three points in the opening four rounds.

Antonio Cassano continues to perform well for Inter, scoring the second goal against Chievo, although playmaker Wesley Sneijder injured a muscle and could be out for a couple weeks, and possibly miss the Milan derby on 7 October.