Andrea Pirlo says his Juventus side are a "work in progress" after they suffered a 2-0 defeat to Barcelona in their Champions League Group G clash on Wednesday.

The Serie A champions - who had Merih Demiral sent off late on after picking up two bookings - were second best to Barca throughout, with Ronald Koeman's side sealing all three points thanks to Ousmane Demeble's deflected strike and Lionel Messi's stoppage-time penalty. 

Juve failed to register a single shot on target, although Alvaro Morata did see three efforts ruled out for offside. 

Pirlo refused to criticize his players, though, and hopes they are able to take positives from the setback.

"We knew it'd be tough against a side that plays good football and is accustomed to playing at this level, whereas we are a work in progress," he told Sky Sport Italia.

"Ultimately, it's a match that will be useful for us to grow and improve in future.

"I hope to have more players back soon because I don't have many options and those I start end up having to play almost 90 minutes twice a week. That's not easy for them, especially when they are young and inexperienced."

Captain Leonardo Bonucci was more critical than his coach, warning his team-mates that they have a "long road ahead of them".

"It's the moment when we need to grit our teeth, work together and get the best out of ourselves," he said.

"The results have not been up to our standards lately. We knew it was tough, even if both teams were missing a lot of players, but we made too many technical mistakes and that made it easier for Barcelona.

"There's a long road ahead of us. We know that we could've done more this evening, including myself, even if I was struggling."