The heat may be on for Ronny Deila as he fights to save his job at Celtic .
Lennon reckons it 's Warburton and Rangers who will wilt in the Old Firm cauldron .
The heat may be on for Ronny Deila as he fights to save his job at Celtic but Lennon reckons it 's Warburton and Rangers who will wilt in the Old Firm cauldron .