No Celtic pardon if Brendan Rodgers commits the ultimate crime and Arne Engels call could be used in evidence

One of the character flaws my wife detected in her husband a long time ago is a form of financial illiteracy.

“You think a pound is a lot of money,” is the observation she frequently makes to substantiate her allegation. Guilty as charged, your honour. But, if it please the court, only to a point. I also have the financial acuity to know that £11million is an awful lot, especially when it is spent to bring a player to a team who already have a superiority over their domestic rivals that’s as long as it is broad.

Arne Engels obliterated Celtic’s record transfer fee in the summer when he joined from Belgium. He was immediately impressive, proving the wisdom of the old saying ‘You get what you pay for’. On that basis, I don’t think it’s outrageous to suggest a player of his calibre might be thought an automatic starter in the first showpiece of the season, the Premier Sports Cup Final against Rangers.

But Engels has started to cut a puzzling figure. His manager Brendan Rodgers was moved to publicly defend Arne when the player’s performance level visibly dipped.

His point about the slow, but sure, transformation of Nicolas Kuhn into a contributor of high standing was well made. But days like this are surely the precise reason why you break the bank to sign a game changer.

Extraordinary money, by Scottish standards, is put out on extraordinary talents and not bit-part players. And that’s what Engels was when Celtic played Dinamo Zagreb in the Champions League tie in Croatia on Tuesday night.

Paolo Bernardo did well in the Balkans. Reo Hatate was hit and miss in the midfield. Luke McCowan is ineligible for the cup final, Callum McGregor, the captain, is undroppable.

Engels was first pick, and first goalscorer, against Hibs in