The 2006 World Cup winner now sports a beard which many feel gives him a resemblance to martial arts film star Chuck Norris, and he has been just as destructive as Juve's guiding light in the past 18 months.
Pirlo's importance was clear on Saturday as he sat out the Serie A match against Lazio through suspension and Juventus, who had scored 10 goals in their previous two games, stuttered to a goalless draw.
Never the happiest-looking of characters with his long, droopy face, Pirlo's favoured role as a deep-lying playmaker makes him something of a rarity in modern football.
The 33-year-old, ever-present in their Champions League campaign to date, dictates the rhythm of the five-man Juventus midfield, floating exquisitely-timed 40 metre passes over the opposing backline or threading gaps in the defence.
The Serie A champions have lost only twice in all competitions since Pirlo joined them at the start of last season from AC Milan where his own career had run into a dead end.
Spain coach Vicente del Bosque suggested recently that Pirlo, also instrumental in leading Italy to the Euro 2012 final, deserved to win the FIFA World Player of the Year award.
Juventus' problem is that their forwards are not always on hand to convert chances that Pirlo and his midfield create for them.
New signing Sebastian Giovinco has failed to meet expectations since his move from Parma and Mirko Vucinic's individualism continues to exasperate his team mates and the fans.
Juventus, who went out in the group stage on their last Champions League appearance in 2009/10, have six points from four games in Group E, one less than Chelsea and Shakhtar Donetsk who visit winless Nordsjaelland.
Chelsea will qualify if they win Tuesday's match and Shakhtar will join them if they also win, leaving Juventus to contemplate the Europa League.
However, a win for Juventus would leave them needing a point from their visit to Shakhtar in December to qualify, as they would edge Chelsea on the head-to-head record if the pair finished level on points.
Chelsea, who in their opening Champions League game squandered a 2-0 lead at home to Juventus in a game that ended 2-2, cannot be eliminated on Tuesday but if they lose and Shakhtar win as expected, their fate will be out of their hands.
WINLESS RUN
"From now on we think about Chelsea, as at this moment it is the most important test," said Juventus defender Leonardo Bonucci.
"Chelsea lost to West Bromwich Albion on Saturday, but that doesn't change anything as far as we are concerned. On Tuesday we must step on to the pitch only to win."
Chelsea have failed to win their last four league matches, their first poor domestic run since Roberto Di Matteo became manager last March.
Di Matteo was angry at the way his side defended at The Hawthorns and said he may change the shape of his team back to a more defensive one rather than the attacking options he has used for most of this season.
"This season we are playing a little bit different but we might have t
