Chris Sutton insists Celtic coming from behind to beat Rangers on Sunday would've been a disaster for the club.
The Hoops were played off the park by Steven Gerrard's side as they claimed a 2-0 victory at Ibrox.
Celtic had already wrapped up the Premiership title before going to the home of their rivals but former Parkhead favourite Sutton believes the result will be a wake-up call.
Indeed, he claims that a Celtic comeback would've papered over the cracks and fuelled a potentially dangerous complacency heading into the summer transfer window.
He told BT Sport : "At 1-0, Celtic could've got back and nicked the game - that would've been the worst thing ever to happen to Celtic, in terms of complacency.
"Everybody can see Celtic need investment in the summer, so it was eye-opening in terms of how well Rangers played, albeit they weren't under pressure.
"But now, Celtic know what they have to do.
"The bottom line is - the squad's not good enough, it needs major investment."
Sutton earlier praised Rangers' performance but believes it's typical of the Ibrox side that they turned on the style when the pressure was off.
Rangers will release a DVD after Celtic victory and meaningless win sums them up - Chris Sutton
Speaking in his exclusive Record Sport column, he added: "Fair play to Rangers. They were at it all afternoon, it was an impressive performance and I’m sure they enjoyed it.
"No doubt there will be a DVD of the game out by the end of the week.
"But let’s face it, the pressure was off and that is when this Rangers team turns up. It’s too little, too late.
"If I was Steven Gerrard I’d be pulling my hair out and wondering where this team was when he needed them back in January and February."
