The Norwegian has named the duo as the players he feels who have shown the greatest transformation with the Bhoys over the course of the season.
“With Nir, I explained what I wanted from him - He really wasn't doing that before in the first month that I was here at the club,” said Deila.
“It was the same thing with Leigh. He was not coming and giving all of himself in training and in games, but in the last few months you can see that it has changed.”
Bitton’s importance in midfield is clear for all to see. He’s a very calm and composed player who sits and dictates the pace and control of Celtic’s play.
He allows Scott Brown to hustle and be aggressive and allows Stefan Johansen to get forward and play in behind the main striker.
Griffiths deserves credit because he’s become the most important forward at the club.
He’s arguably ahead of Anthony Stokes and John Guidetti in the pecking order and is crucial in the way he works hard, trying to stretch opposition defences, creating spaces for the side’s midfielders to exploit.
Both players need to have a good game this weekend in the League Cup final against Dundee United, for the Bhoys to produce an effective performance and secure Ronny Deila his first trophy in charge.