Kris Boyd has been branded a 'fool' by Chris Sutton in an on-air verbal spat regarding Celtic's Champions League record this season.

Brendan Rodgers' side lost 2-0 in their latest European fixture on Tuesday night against Lazio. That result confirmed the club wouldn't feature in the Champions League or Europa League after Christmas.

On several occasions now Rodgers has gone on record to state his squad needs strengthening if Celtic are to progress on the European front.

And speaking ahead of today's game at McDiarmid Park versus St Johnstone, Sutton and Boyd argued over their differing viewpoints.

The latter said: "I know it's easy to say Celtic will get to January but they are not going to have European football. Why would the Celtic board (spend) ... I mean, everybody tells me they are the best team in Scotland by a country mile. Why would you want to go and spend an absolute fortune in January to go and win the league again?

"Looking at Celtic, it's as if they have enough to do what they need to do in Scotland and they'll bank the rest of the money. They don't need go and spend an absolute fortune. Do Celtic just do enough to get past in Scotland. We keep hearing Celtic have got to invest to compete in Europe but we don't see it."

Sutton responded: "You didn’t half waffle some nonsense there. Why would Celtic want to build in January? That's a rally strange comment, why would Celtic want to get better? Brendan Rodgers is basically saying this squad isn't good enough."

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Sutton continued: "Let's not make excuses for Celtic in the Champions League. We are seeing Copenhagen, a team you would put on par with Celtic, who are competing in the Champions League.

"The point Kris makes about Celtic basically not needing to sign players in January was utterly ridiculous. Of course they are going to sign players if Brendan Rodgers thinks they are not at the level." Boyd interjected to say "I think people forget they spent a fortune in the summer as well" and to claim he hadn't seen Sutton criticise things.

That wasn't something the former Celtic striker was happy about. He added: "Hang on a minute, I have just criticised them for the last three or four minutes. You are talking absolute nonsense. It's an amazing concept you don't understand a manager wants to sign players in January to get better."

Boyd then said: "After signing eight in the summer?"

And this is where Sutton stuck the boot in, saying: "That was then, that was the past you fool! Idiot."