Neil Robertson suffered a shock exit at the hands of world number 94 Ross Muir in the second round of the Scottish Open.

Robertson, ranked ninth in the world, was initially frustrated at what he perceived to be slow play from Muir, who averaged 31.2 seconds per shot to Robertson’s 25.2 during Muir’s 4-2 win.

After the match, Robertson said: “It was a bit of a farce, really. I think the referee should have stepped in midway through the match and told Ross to pick up the pace.

“Two and a half hours for six frames of snooker is an absolutely joke and certainly not the way I play the game.

“The way Ross plays – he did well to win the match but playing like that, you’re not going to go very far in the game and a stronger official would have done something about that.”

However, Muir revealed in his post-match comments that he was suffering from eye migraines, which significantly contributes towards his slower pace around the baize.

Australian potter Robertson then took to Twitter to issue an apology due to being unaware of Muir’s condition.

“I would like to apologise to Ross. I let myself down in the interview which was seconds after the match,” the Thunder from Down Under posted.

“Incredibly disappointed with the conditions today and as defending champion it only made it more frustrating. I was unaware of his health problems and hope he gets better.”

Muir, meanwhile, was delighted to get his victory over the defending champion as he set up a third-round clash against Sam Baird.

“It’s a very, very good win, Neil is a top player and a former world champion. I’ve had some issues with my eye over the past 18 months really, but the last month, including the UK Championships, it was getting pretty bad.

“I suffer from eye migraines from the bright lights. My vision in my right eye gets quite blurry – it’s not very nice and tends to get much worse when the pressure is on as well.

“Every player plays at his own pace, I’m not doing anything wrong and I’m giving it my all, which is what every player should do in order to get the best out of their performance.

“Sometimes, when I’m struggling with my eye I need to take a bit more time.”

Watch the Scottish Open LIVE on Eurosport and Eurosport Player with analysis from Jimmy White and Neal Foulds