Andy Walker claims Neil Lennon's tactics and transfer policy must be called into question following Celtic's shock Champions League exit.
Former Celtic striker Walker is critical of the decisions to play Olivier Ntcham, who reportedly wants to quit Scottish football while deploying midfielder Callum McGregor at left-back and believes both played a major role in the defeat to Cluj.
Speaking to Sky Sports News, Walker said: "I'm sure Lennon will be happy to accept his part of the blame. To play McGregor at left-back, that's happened before and it didn't work.
"You are taking arguably Celtic's most creative player out of midfield in favour of someone like Ntcham, who said only very recently that he doesn't want to be at the club, and that he's too good for Scottish football
"The team last night has a lot of talent from middle to front but McGregor should be in the middle of the park. Defensively Celtic need strengthening