The 17-year-old is the youngest Norwegian to captain his club - and the former Celtic man thinks Parkhead is the right place for him.
The suggestions are that Ajer has caught Celtic's eye as well as the likes of Tottenham Hotspur and Liverpool.
And Riseth is quoted as saying that the Bhoys would be the best option for the teenager by the Herald: "It is the same with Martin [Odegaard] at Real Madrid. We all know his talent and we can see how much potential he has but it is not always so straightforward when you are at a top club.
"One thing about Ronny is that he has a good track record of getting the best out of young talent and this is probably the right time for Kristoffer to think of going to the next level.
"Ronny is the kind of manager who can get the best out of him without putting him under too much pressure. He is sensible that way."
Using Odegaard as an example is a point well made by Riseth. At the same time, though, it seems like the former Celtic midfielder is claiming the Bhoys are a 'smaller' option for Ajer and that they should try and exploit that.
Many fans probably wouldn't agree with that assessment. Deila's track record with youngsters, however, is definitely a point worth emphasising.
At 17, Ajer could well benefit from the Norwegian's way of doing things. Some supporters were interviewed on Sky Sports News recently and suggested Deila's promotion of youth is the only reason he is still at Celtic.
It is also worth emphasising, though, just like with Odegaard, that a 17-year-old will never make or break a season. It the Ajer speculation all much ado about nothing?