Massimiliano Allegri's men have been held to a trio of draws in succession, playing out a goalless match with Atletico Madrid in the UEFA Champions League between league stalemates against Fiorentina and Sampdoria respectively.
As a result, Juve were forced to settle for a second-place finish in their Champions League group, while their lead over Roma at the top of Serie A has been cut to just one point.
Up next for Juve is a trip to struggling Cagliari on Thursday and they may be without coach Allegri after he picked up a one-match touchline ban for expletive remarks made to officials during the draw with Sampdoria, though the club lodged an appeal on Tuesday.
Barzagli, who is nearing a return from an Achilles injury, is not worried about the champions' form, reminding critics that they are still top of the table.
"We played against three big, physical sides," the centre-back told Juve's official website.
"But the important thing is we're still top. It's a long season, and we have to stay as focused as ever."
Juve will be expected to take all three points away from Stadio Sant'Elia, with Cagliari having failed to register a single win in the last 10 meetings between the sides across all competitions.
Cagliari's last win over Juve came in the shape of a 2-0 triumph at home in November 2009, but few will envisage a similar outcome this time around.
Zdenek Zeman's side head into the clash third from bottom in Serie A, ahead of only Cesena and Parma.
Cagliari have won none of their last seven fixtures in the league, a run which includes home defeats to Fiorentina and Chievo.
The Sardinia-based club were held to a 0-0 draw at rock-bottom Parma last time out and under-fire coach Zeman has acknowledged that his players are worried about their precarious position.
He told Radio Rai: "The mentality of the lads was correct and we controlled the ball well, even if we were lacking something up front.
"It was hardly an epic match, as you could tell both teams were worried about their current situations."
While Juve could be without Allegri, they definitely will not be able to call upon the services of suspended defender Leonardo Bonucci.
Cagliari continue to miss goalkeeper Simone Colombi (wrist) and striker Marco Sau (thigh), with neither expected back until early 2015.
