Post-match analysis of Celtic’s performance in the Hampden showdown, which they lost to Rangers on penalties after a 2-2 draw over 120 minutes, focused heavily on the physical conditioning of Deila’s team.
Several pundits and ex-players, including former Celtic captain Paul McStay, questioned the fitness of the Scottish champions which appeared inferior to that of Championship winners Rangers.
That has sparked a scornful response from 37-goal striker Griffiths who insists Celtic’s defeat at the national stadium was purely down to their failure to properly carry out their pre-match strategy.
“For people to say we are not fit enough is bollocks,” said the 25-year-old. “We ran for 120 minutes last Sunday. At the end of games, we are still pressing on when other teams are dead on their feet. That’s why we have scored late goals this season.
“Sunday was disappointing because we had a gameplan where our defence was supposed to push up a bit, while Scott Brown and Nir Bitton were also supposed to push up from midfield.
“That should then have given Stefan Johansen a licence to come and help me in attack. It didn’t happen, in the first half especially. After half-time, we kind of worked on what the gaffer had wanted. If we had started that way, I’m sure we would have won the game.”
As Celtic look for a successor to Deila, who will leave at the end of the season, Griffiths believes Neil Lennon – who signed him for the club in January 2014 – is a strong candidate to return for a second spell in charge.
“Lenny has been associated with Celtic one way or another for the last 15 years,” said Griffiths. “The fact he is not in a job at the moment gives him a good chance.
“There are managers who aren’t in a job right now who will be licking their lips at a chance of the Celtic job. The club is massive, the biggest in Scotland and one of the biggest in the world.
“Any manager being linked with the Celtic job will be happy. It’s a chance to turn this around and make us a Champions League team again. There are big names out there looking forward to hopefully getting an interview.
“It’s entirely up to the board now, whoever they decide to bring in.
“Our focus as players is to give the current manager a perfect send-off by making sure he wins that title again this season.”