Martin O'Neill is, by and large, the eternal diplomat. The Celtic manager occasionally loses his cool, and did so memorably in Turin earlier in his club's Champions League campaign when a hugely controversial late penalty gave Juventus victory, but otherwise he is not prone to public tantrums.

He is well aware that what goes around comes around in football, and because of that tends not to speak ill of others within the game.

Yet, on the eve of the Scottish champions' crucial European tie against Rosenborg in Glasgow, the Irishman found himself seriously at odds with Belgium over their use of his defender Joos Valgaeren last weekend.

The fact that Valgaeren was on the substitutes bench for the Belgians in Croatia and did not play appears not to have prevented him from picking up an injury that makes him doubtful for tonight. "It's an unusual situation," O'Neill said through gritted teeth. "We have been easing Joos through following his recent cartilage operation, but it seems he trained very hard when he was over there.

"Now, because of that, he is causing us some anxiety for the Rosenborg match, and I don't think it would happen in any other walk of life that people take someone away who you pay and who you insure yet it is you who are left to suffer the consequences.

"Our club doctor spoke to the Belgian doctor and Joos even took his scans with him, so what's happened is disappointing."

That is tantamount to fierce criticism from O'Neill, who understands international managers' problems and equally will never stop his players from playing for their countries, but in the final analysis his only concern is Celtic.

O'Neill, who watched from the directors' box as his side beat Porto, will be back on the touchline again after his one-match ban.

Valgaeren is now struggling, Bobby Petta and Tom Boyd are definitely out and Neil Lennon continues to be nursed through matches with a groin problem that will inevitably cause him to miss some forthcoming Premier League fixtures.

That leaves O'Neill a little understrength for what he knows will be another hugely demanding test for his Champions League newcomers after their victory over Porto. And Rosenborg are old hands at this level.

The main threats to Celtic will come from the former Parkhead player Harald Brattbakk, who has an excellent pedigree in this tournament but failed to live up to expectations during his spell in Glasgow, and the midfield general Bent Skammelsrud, who admitted his team had put unnecessary pressure on themselves by losing their opening game at home to Porto.

"This is now a massive week for us, starting with Celtic and then what amounts to a Norwegian title-decider against Lillestrom at the weekend, followed by Juventus in Turin next midweek," he said.