Marcello Lippi has praised Celtic's team spirit but warned them that there are similarities between the current Juventus side and the one which he managed to Champions League success in 1996.
Lippi, 64, is now in charge of Chinese side Guangzhou Evergrande but took time to assess Tuesday's meeting between the Scottish and Italian champions, praising the recent accomplishments of both sides.
"Everyone has been impressed by Celtic's results in the Champions League this year," the 2006 World Cup winning manager said. "They've got a good young coach and having watched some of their games, the team has a closeness and a compactness that they haven't had before. The team know how to fight for one another but they also have some good individual players.
"But Juventus are a strong side and I know they are very motivated to get through the tie and make progress in this competition. The Champions League has always been a very important tournament for the club and they're determined to go as far as they can this year."
Lippi believes the Bianconeri are not among the favourites to win the famous trophy this season, but says they are capable of challenging the elite clubs who are tipped for success.
"For me, there are four clubs left in the draw who are a few rungs above everyone else: Barcelona, Real Madrid, Manchester United and Bayern Munich," he said.
"These teams are the favourites but there's no doubt Juventus have quality and will be aiming to challenge. People say that not winning the Champions League since 1996 is too long for a club like Juventus but they need to understand it's an incredibly difficult tournament to win.
"Since 1996, Juventus have reached three finals, all under me, and that's no small achievement in itself given how tough the Champions League actually is. Even getting to the final is very, very hard and when you're there, it can happen that you play well but lose on penalties or by another small margin like that."