Aberdeen boss Derek McInnes has accused Celtic assistant manager John Collins of disrespecting Scottish football.
The Hoops chief recently claimed that rival teams were not quick or smart enough to challenge his side at the top of the table.
McInnes has now hit back at these "disparaging" comments, while also suggesting that Celtic do not find life as easy as their assistant makes out.
"He's got a lot to say for an assistant manager, to be honest. He's entitled to his opinion but if it was that easy they would win the treble every year," McInnes is quoted as saying by the Daily Record.
"I think it's very disparaging, it's a poor comment. Whether he thinks that or not, I think it's disrespectful to the rest of the league to say that. It's disappointing.
"There is a level of competition there that can test them and I think what he said is a slap in the face to the rest of the league."
Aberdeen finished 17 points behind Celtic in the Scottish Premiership last season.