The Slovene was formerly a player with Maribor and observed first hand the talents of Brazilian striker Tavares.
The Celtic players will be given the same opportunity tomorrow evening when they contest the first leg of their Champions League play-off tie with Maribor. Having joined Maribor at the age of 10, Celcer will follow events in Slovenia with interest but acknowledged last night that the Scottish champions will have a greater chance of gaining an advantage in the tie if they can keep Tavares quiet.
"The striker Marcos Tavares, is a very big favourite with the fans," said the County defender. "He is the top club scorer of all time. They love 'Tava' and Celtic should beware.
"He is not only a decent finisher but a real leader of the team. So much in the game comes through him. I would say he's the man that Celtic must stop to win the tie. Marcos is actually the only player left there who I played alongside when I was at Maribor, but I have played against them with Gorica for the last few seasons.
"They also have this player Agim Ibraimi, a right winger from Macedonia who has come back from a loan at Cagliari in Serie A. He is excellent, too, a big threat, but they have many good players. I can vouch for the fact they are strong right through the team.
"They are the Slovenian national champions for a reason and have been for five of the last six seasons. They are also a really compact unit, so it's going to be tough for Celtic."