The 32-year-old has been immense for the Bhoys so far this season and has recently been linked with a shock summer switch to Premier League leaders and recently crowned Capital One Cup champions Chelsea.
Deila, though, says Celtic absolutely can't sell the experienced shot stopper, who has been particularly impressive on the grand stage in the Europa League.
Gordon's Scottish Premiership form has been spectacular, too, making it understandable that Deila wouldn't want to part company with the former Sunderland goalkeeper.
So understandable, in fact, that the Norwegian says he understands why others, like Chelsea perhaps, are interested in Gordon - but wants to keep the shot stopper at Celtic Park until he retires.
“I can’t sell him. I don’t want to. I want him here for the rest of his career. Hopefully that can happen," the Bhoys boss told reporters.
“At this level, he’s an important player for us. He’s a great keeper and he’s a man we want to keep at the club. I understand why other clubs are looking at him because he’s had a fantastic season."
Celtic host St Johnstone on Wednesday night, a game that could take them nine points clear of second-placed Aberdeen should they secure victory.
That would put Deila's men in the strongest position possible when it comes to Celtic's title defence, while a cup double (and therefore overall domestic treble) is also still on the cards. Would the Hoops be anywhere near their current level without Gordon, though?