Leinster are rank outsiders heading into Sunday’s European Rugby Champions Cup encounter with Toulon, but former Blues forward Victor Costello isn’t ruling out the prospect of an upset in Stade Mayol.

Speaking at the Aviva Stadium yesterday afternoon, Costello — who played alongside current Leinster head coach Leo Cullen at club, provincial and international level — revealed that he views Toulon as a “mercenary” outfit, and although he acknowledges that they are formidable — he feels that his old side could claim a win if they stand up to the star-studded champions.

“If they can dig deep into their own tradition and their own belief, they’re good players. I think they can upset. This is a mercenary side. You can silence the French crowd, they can turn on themselves. It’s a tough ask, but it can be done,” Costello remarked.

“I don’t have anything against Toulon, but they’re not what I would want in our game. Which is a bunch of guys with a pension, and they’re winning. But I firmly believe they’re only winning because nobody stood up to them.

“If you put the old Leinster team, or the old Munster of old against Toulon, they’d kick them up and down the pitch. There’s no real tradition with any of them there. No loyalty, I don’t believe, but they’re good. Skilful, talented, experienced, but if you can get under that, and push them to play with their heart, you might expose them.”

However, Costello does feel that there is too much of a distraction in the lead up to games of this nature, and with speculation growing about the futures of Leinster duo Ian Madigan and Ben Te’o, he expressed a desire for agents to be regulated in how they conduct their business.

“I think there’s a lot of distractions, a huge amount of distractions. Everyone’s making excuses about the World Cup and it is 20 players from Leinster. What I don’t like is players explaining themselves. If you look at the way a rugby week works, it hasn’t changed that much.

“I think [Anthony] Foley and Leo… Axel has been there for longer, but Leo will need time. The personnel, the players are still there, there’s a fatigue factor and then there’s the fact of the leaving with Madigan and Te’o. That’s never good, when there’s uncertainty for players’ futures or the future of the club.

“Agents, or whoever, the IRFU, agents need to be regulated, need to get this sorted and get it out of the way. I know the World Cup was there, they couldn’t do it then, but get it done beforehand. Because that type of talk in a dressing room in the lead up to a Toulon game is just another distraction, of which there’s been many.”

Costello was joined in the Aviva by Paul Wallace and Malcolm O’Kelly, who all featured on the first Leinster team to compete in a European game 20 years ago against Milan. This landmark game will be commemorated at half-time in tomorrow week’s return fixture with Toulon, and reflecting on the province’s early adventures in the competition, Costello said that the successes of Ulster and Munster paved the way for Leinster’s later Heineken Cup triumphs.

“Obviously at the moment, there is a transition going on. For Ireland, it’s great to have those provincial club games in the lead up to European games. Obviously Ulster got there first, but Munster, they really paved the way. They really did.

“And I suppose a lot of the success [for Leinster] comes from the confidence that came from the first win in 2009 and beating Munster at Croke Park in the way they did,” Costello added.