Mark Viduka insists Celtic have the greatest fans in the world.
But he has predicted Dinamo Zagreb to edge the Champions League showdown in the battle of his former clubs.
The Australian owns a coffee shop in the Croatian capital and will be at the Maksimir Stadium as a guest of Dinamo.
He moved from Dinamo Zagreb to Celtic in a £3.5 million move in 1998 and after a bumpy start, when he returned home Down Under after citing stress, he eventually became a Hoops hero after netting 27 goals in his only full season before sealing a big money move to Leeds United after just 18 months at Parkhead.
But although he has nothing but good memories of Celtic, he still thinks they might come unstuck tonight despite Dinamo Zagreb's dreadful recent form and long injury list. Viduka said: "I had a great time. Celtic is not a club, it's an institution. The fans are probably the best in the world.
"I played, I would say, maybe my best football of my career. I was the top scorer in the league, I was also named the best player in the Scottish league.
"I have wonderful memories of Celtic. When you run onto the pitch in that stadium in front of 60,000 people, it's a fantastic experience. It's also a big responsibility, but also a pleasure. When you score a goal for such a club, it's an honour.
"The whole community is in the stands, from old ladies to children. Everyone lives for Celtic. Wherever we have been in the world, their fans are there.
"As far as the club is concerned, Celtic are really a giant. Unfortunately, the Scottish League is not as strong as the English Premier League."
Read more:
However, Viduka, in an interview in his adopted homeland, believes Brendan Rodgers' side could still struggle.
He pointed out: "Dinamo has the advantage because they are at home, that's my feeling. Even though they're not in great form in the Croatian league right now. Dinamo has always been strong at home in European competitions.
"Celtic are in form, that's obvious. Dinamo has injuries to important players like Bruno Petkovic, Arijan Ademi, Josip Misic, Petar Sucic, but I would say that they are still the favourites at home.
"It's hard to play on two fronts, especially when it comes to the Champions League. At the time, when I was playing in the Champions League with Leeds United, that was a problem for us too. We didn't have a particularly large number of quality players, so a few injuries can disrupt everything.
"You know how it is when you play twice a week, it's enough to get one knock and you're not fit for a few days, and the games come one after the other. You need time to recover. It's not easy.
"And Dinamo has another challenge – all the teams in the Croatian league are going to bite against them to the max. These are their biggest games of the season and when they play so committedly, there's a great chance of getting a result."
