The Bhoys must beat Ajax if they are to stand a chance of progressing from Group A of the Europa League and Bonner has warned against the temptation of playing 'the Celtic way.'
And he believes Deila must be more 'adaptable' if the Hoops are to get anything from Thursday night's crunch clash against the Dutch outfit.
Bonner is quoted as saying by BT Sport: "I've always said in Europe you have to be more cautious. You can't play the normal way Celtic play, especially under Ronny when they push full-backs forward and almost leave it two v one at the back.
"I think you've got to be a bit more adaptable and change it a bit to get a chance."
Bonner does feel Ajax can be got at - and Celtic showed during their opening Europa League clash that they can outplay the Dutch side.
But will the real Celtic show up? When the Bhoys took the lead against Ajax in the reverse fixture, they surrendered it with ease.
They were then pegged back again v Fenerbahce and followed that up with two awful, awful performances against Molde.
Can Celtic produce a solid 90-minute display for the first time this group stage against Ajax or will Deila fail to adapt tactically once more?