CALLUM McGREGOR believes Celtic’s ‘unacceptable’ loss to Rangers is a timely reminder there are no meaningless derbies.

Already crowned Premiership winners after beating Hearts last week, the Parkhead captain confessed the champions were ‘miles off’ the required standard as strikes from Todd Cantwell, John Souttar and Fashion Sakala earned the home side a deserved victory at Ibrox.

Rangers had previously made a bad habit of failing to capitalise on big opportunities in these matches, but they ruthlessly punished Celtic with a trio of goals McGregor believes arrived at crucial times in the game.

The result means little in the context of this season, but the Parkhead skipper is adamant that is no excuse for not delivering a performance for their fans. He expects Rangers to mount a stronger challenge next season, and insists Celtic must be ready to further improve themselves.

“We were miles off our usual level,” the 29-year-old midfielder said. “And that’s what happens in this type of game if you’re not at the races, you give yourself a lot to do.

“They scored at good times in the game and that took it away from us. We have to take our medicine, accept that we were poor, that we didn’t deserve anything out of the game.

“We just didn’t perform. If you turn up and play like that you can’t expect to get anything out of the game.

“Home advantage always plays a part in this game. They score early, it gives them a lift and gives the crowd a lift.

“We made it difficult for ourselves. At times, we’ve been able to come back from that but today we weren’t at the level.

“I don’t think there’s much else to say, other than we had a bad day. We have to understand what that means for us a group, and for the supporters

“It’s unacceptable. We have to dust ourselves down and we’ll go again.

“We still have three games to go in the league and a big cup final. When that’s done we start all over again from nothing the following season.

“It’s a timely reminder of what this fixture means all the time, regardless. You expect that from Rangers [to come back stronger next year].

“That’s what the league is: it’s competitive. We’re pushing to get better, they’re pushing to get better.

“Every team is going to improve in the summer and we’re not immune to that either, we have to get better. You see today, if you’re not at the level that’s what can happen.

“Like I said, it’s a timely reminder.”