When Nick Walsh brandished a red card to Stephen Kingsley back in November, the Heart of Midlothian defender was adamant the referee had made a mistake. 

The official adjudged Kingsley to have dived in the Rangers box toward the end of the League Cup semi-final. He duly issued a second yellow card before VAR intervened.

Walsh, on a review, saw his mistake, cancelling the red card and awarding Hearts a penalty. Lawrence Shankland scored from 12 yards for what was no more than a consolation in the 3-1 defeat.

Looking back on that decision now it played a big part in a remarkable but overlooked statistic: Hearts didn't pick up a red card in the season just past.

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It was the first time the team did not have a man sent off in 36 years, since the 1987/88 campaign.

The zero red cards was a stark improvement from the season previous when the team had 15, albeit Peter Haring's sending-off at St Mirren was correctly reduced to a yellow card following an appeal.

Steven Naismith told Hearts Standard that it wasn't something ahead of the season that the coaching staff "had to highlight". Instead, it may have been a consequence of the way the team played and how players were managed when on a tightrope.

He also highlighted his feeling that the team had been soft. But eradicating that didn't mean losing any fight.

"The way we played and we had more control in the games there were less reactive situations that caused concern," Naismith said. 

"I think we did have a fight in the team, we weren’t soft. I think in the season before in the seven games I thought we were a bit soft and a bit weak. I don’t think that was shown this season. When players were isolated one v one mostly full-backs and centre halves very rarely did we get bullied.

"That was something I was pleased with that we managed to stop that happening or give away stupid fouls that do lead to cards. It wasn’t something specific but it is a good trait to have that we are not putting ourselves in vulnerable situations where we need to watch what we are doing."

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Another aspect was game and player management.

It is no surprise that Cammy Devlin had the most number of yellow cards with 13 - one more than Lawrence Shankland - such is the way he plays the game. On a few occasions, he would be replaced not long after. That was part of the coaching staff's management. They were more than willing to switch a player if they felt it was required to avoid a possible red card.

"There were probably a couple of occasions throughout the season where players we running a fine line but, going back to the group, I’d take somebody off and put someone on to stop that happening," Naismith said.