The Bhoys head coach is 'so happy' for the 23-year-old.
The forward netted twice as the Hoops romped to a 3-0 win, bouncing back from further Europa League disappointment with further Scottish Premiership success.
And Deila knows full well that an in-form Ciftci reduces the pressure on main striker Leigh Griffiths.
Indeed, the Norwegian now feels Celtic don't have to solely rely on top scorer Griffiths up top.
RD: "I'm so happy for Nadir today. Now he has had 2 games in a row and we know he can do things. Today he was strong and scored twice." (MH)— Celtic Football Club (@celticfc) December 13, 2015
RD: "We know we don't have to rely on Leigh all the time." (MH)— Celtic Football Club (@celticfc) December 13, 2015
Ciftci has received plenty of criticism since his arrival at Parkhead but has the 23-year-old now proven he is good enough to play for Celtic?
The jury will probably still be out on the forward among those who disapprove of his summer signing. Others may be more impressed after his performance against St Johnstone. Deila certainly is.
And, whether it's Ciftci or Carlton Cole, any side will be pleased to have other options than their main striker. Griffiths should be relieved - and Celtic fans hopeful, if not already pleased.
Next up for the Scottish champions is a home game against Motherwell, before Deila's men travel to Hearts.