Celtic manager Brendan Rodgers has played down the reaction of Leigh Griffiths after he was substituted during Thursday night's 5-0 win over Partick Thistle in the Scottish Premiership.

Griffiths was handed just his 14th league start of the season at Firhill and marked the occasion with the opening goal, but that did not prevent Rodgers from taking him off to be replaced by Scott Sinclair shortly after the hour mark.

The Scotland international made his unhappiness at the decision known on his way off the field, but Rodgers revealed that he has since apologised for his reaction.

"I spoke to him this morning at length. He was fine. He apologised sincerely for his reaction. It wasn't the right reaction. It's not one that I expect and, more importantly, the rest of his teammates expect. He is a really good fella, a good boy and a massive part of what I am doing here. So please don't think he is on his way out or this sort of stuff," he told reporters.

"It has been frustrating for him this season. He has had a multitude of injuries, sick, not able to train as much as he would like and to see the team do so well, and him not playing as much as he would have liked. I understand the frustration. He probably thought he was brought off because he was playing bad and it was totally the opposite.

"I thought he was excellent last night and as the only fit striker at the club I wanted to protect him, like Dedryck Boyata and like I did with the others. I'm now much more experienced as a manager so I can have a wee bit more empathy about what he was thinking. But at the same time it's not something we tolerate either.

"It's very important that we are a collective and everything stays in house, that's the way it's always been. Draw a line under it now and we move on and he will start and be ready for Hearts at the weekend."

Celtic will go into their last league game of the season at home to Hearts knowing that victory would complete an unbeaten Premiership campaign.