The Hoops fell behind twice against St Mirren in the first half and the former goalkeeper thinks off-field matters at Parkhead are translating negatively on the pitch.
Speaking as co-commentator on BBC Sportsound’s coverage of Celtic’s 2-1 Premiership defeat to the Buddies, Bonner raised concerns at the performance and urged action on Neil Lennon’s future, recruitment and departures as next season is “such an important situation now.”
The process is underway with the club revealing Scottish Rugby’s chief executive Dominic McKay would be moving to the same role at Parkhead this summer, but Bonner believes there are more decisions to be made.
"Obviously with Peter Lawwell making his announcement, nobody’s sure what’s going to happen,” the former Celtic goalkeeper said. “Neil Lennon – I assume that decision will have to be made pretty soon also, to clear the way for next year because next year’s such an important situation now.
“They have to plan ahead and know exactly who the manager is and then get the recruitment done, clear some people out. Everybody is unsure now where that’s going and you can see within the team. That’s the problem.
“They’re so off it compared what they used to be.
"Imagine if the fans were inside the ground and how they’d react to it.”
Kristian Dennis fired St Mirren in front with a well-taken volley before Odsonne Edouard equalised with a well taken finish of his own.
However blunders from Kris Ajer then Shane Duffy let Ilkay Durmus free to fire in Saints’ second.