Following Kilmarnock’s win against Celtic in September, Boyd said that there was a divide in Premiership champions’ dressing room. He stood by his comments when challenged during a BBC interview released on Saturday.
He said: “For me it’s plain to see. I don’t think Celtic have been at the level they’ve been at. I’m not going to say something without having something to back it up.
“I’m not going to sit here and say exactly what it is.”
Boyd did admit that his information did not come directly from the Celtic dressing room, but re-iterated, “I know exactly what is going on.”
The striker, who hasn’t played for Kilmarnock since a 3-2 defeat to Hibernian on the 15th September, also commented that Celtic were playing below their normal high standards.
“It’s clear to see that Celtic have dropped dramatically from where they were. A team like Celtic, with the amount of opportunities they create should be scoring two or three goals every week.
“I know we maybe became used to that, but I don’t think much has changed and I think the players are under-performing at the level that they should be. Saying that, they’ve performed at a top level for a number of years, so it can be difficult to continue that.”
Boyd was rebuked by Celtic manager Brendan Rodgers after his original comments about the Parkhead split, stating that the striker is “probably best suited to getting himself into the Kilmarnock team to get playing.”
The former Rangers forward has struggled to find his way past the first choice strike pairing of Eamonn Brophy and Greg Stewart so far this season and has yet to score in the Premiership.