The 33-year-old moved to Parkhead after spending around two years away from the professional game.
The Scotland stopper joined the Scottish Premiership side in 2014 despite being without a club for the previous two years. But despite his past injury record leading many to write off his career while he was out of the game, his recent involvement for the national side against Denmark saw him make his 100th appearance for club and country since his comeback.
And Deila explained how invaluable the 33-year-old has been to the Hoops since he joined them.
"If you have a good goalkeeper and a goalscorer then you can go far," he told the Evening Times.
"You can play as much as you want out on the pitch but if you don't put the ball in the goal or if you don't have a goalkeeper who saves balls when they need to then you will drop points. In that aspect he has been very important. We have conceded very few goals lately – I think in the last seven games we have kept five clean sheets – so that is a good thing."
Despite his time at former club Sunderland being plagued by problems, Gordon has arguably been as reliable as any other player in the Bhoys' squad when it has come to staying injury-free.
His desire to avoid further time on the sidelines has clearly not affected his ability either. Celtic conceded just 17 goals in the league last season, and have only let in 23 this time around.
And Deila will be hoping that he continues to remain solid as that would go a long way to helping the club secure the league title and potentially the Scottish Cup crown also.