Indeed, should Celtic make the group stages, Riseth believes there is only one way they can enjoy a solid group campaign and try and make the knockout stages: by spending big and bringing in high-profile names this summer.
Otherwise, the former Hoops man feels the group stage will always be Celtic's limit - until Ronny Deila's youngsters have developed after around two to three years.
Deila's men were knocked out not once but twice in the competition's qualifying rounds last season but are a much stronger unit a campaign on.
Riseth told reporters: "If they qualify for the group, then that will be the highest they can go because it will be tough for them. To do well at that level, they have to bring in big names.
"The club has to decide if it wants to spend money on big names, because if they do that and get into the group stages, the money will come back to them.
"If they don't, then they have to give Ronny and his young players two or three years to develop, when they will then be able to take the next step."
It all comes down to Celtic's aims and ambitions at the end of the day, of course.
Third place in the group could mean Champions League football and the prospect of a longer run in the Europa league. After missing out on the competition as a whole this term, meanwhile, the Bhoys could be content enough simply to make the group, play six games and take the income they would generate from it.
Or, as Riseth suggests, Celtic could go for the jugular...