Bitton was a bit-part player for the Bhoys when Deila took over, with the Norwegian feeling that he was too negative when in possession.
However, the Israel international has made rapid strides after watching Brown and Johansen closely, and he now plays a crucial role in Celtic's starting line-up.
"He [Bitton] had to be quicker on the ball and go forward as everything went sideways," Deila said. "His passing accuracy was 90 per cent. But 50 per cent of that was sideways.
“So I asked him to look at Stefan Johansen and Scott Brown who had 68 per cent going forward. They only had 81 per cent accuracy but I said to him if he could improve going forward and stay at 90 per cent he’d be world class. Now he penetrates much more."
Bitton is now firmly established in Celtic's starting XI, and is regarded as one of the most valuable members of the Scottish Premiership champion's squad.
Capable of going forward, but also solid heading the other way, he provides a great shield in front of the defence and has been one of Deila's men's most consistent performers to date.
Indeed, Bitton has arguably had a better season than the two players he was told to learn from so far, with the 23-year-old regularly out-performing Brown and Johansen.
Bitton has already made 14 appearances for club and country this term, and has scored four goals over that period, highlighting his new-found attacking intent.