(Reuters) - Juventus have a perfect defensive record in Serie A with six clean sheets but the second-placed side have injuries to contend with after key players were sidelined ahead of Cagliari's visit on Sunday.
Thiago Motta's side have not conceded a goal yet in six rounds but that could change with centre back Gleison Bremer -- a pivotal figure in Juve's defence and the only player to play every minute so far -- potentially out for the season.
Cagliari, 16th with five points, may not prove the sternest of tests, but in the long run, Motta will need a replacement with the Brazilian going under the knife after injuring his anterior cruciate ligament.
The centre back, who leads the team in tackles, interceptions and clearances, was forced off six minutes into their Champions League encounter with RB Leipzig following a challenge from Lois Openda.
To make matters worse for Motta, winger Nico Gonzalez also went off with a thigh muscle injury in the same game.
The seventh round of Serie A kicks off on Friday with Antonio Conte's Napoli taking on Como at home.
Having faced his former player Motta last month, Conte will come face-to-face with another player he coached in Cesc Fabregas, Como's manager who won a Premier League title and the FA Cup under the Italian at Chelsea.
After a winless start to the season, Como have turned things around with two victories on the trot to move up to 10th but unlike Juve, their defensive frailties have been exposed and they have yet to keep a clean sheet.
SECOND-WORST DEFENSIVE RECORD
Fabregas's side have conceded 11 goals in their first six matches - the joint second-worst record in the league behind Atalanta and Parma with 12 each.
"We can't keep conceding two goals in every match, so we should keep analysing our mistakes and improve," Fabregas said.
Napoli's attack will pose significant challenges, however, with Khvicha Kvaratskhelia leading the side with three goals and two assists while Conte said Belgian striker Romelu Lukaku is nearing full match fitness.
AC Milan's manager Paulo Fonseca faces another test on Sunday as his team travels to Fiorentina ahead of the international break.
Key striker Alvaro Morata is likely to return to Milan's starting lineup after a series of injuries relegated him to the bench and substitute appearances in recent games.
The Spaniard has two goals and an assist this season but injuries have affected his integration into the attack.
But his impact on the team has been significant, with a noticeable difference in Milan's performance when he is on the pitch compared to when he is sidelined.
Milan's Portuguese coach Fonseca has been feeling the heat due to inconsistent results and the return of a fit Morata could provide a much-needed boost for Milan before the international break.
(Reporting by Tommy Lund in Gdansk; Editing by Toby Davis)