Former Ajax player De Boer – that spent years at Ibrox in 2000 – is just a youth coach with the Amsterdam club.
“You have to have an identity together with your players,” he told BBC Scotland.
“when you have 1 1 foreign players, people do not care if the answers are not still there. Individuals would prefer to see that than a player that you purchased for a whole lot countless, if you have your home grown player.
“Your resources are limited but if you concentrate on the youth from seven and six years old, the entire organisation can be assembled up. That’s exactly what I see from the amateur teams to the teams.
“You have to have a doctrine of where you want to be in a certain stage. I think that’s extremely important, therefore if you put a time, I think in a decade then you might have any results.”
Premiership name holders Celtic failed to reach the Champions League group stages this season, but realized that the final 32 of their Europa League while Rangers featured from the groupstage of the contest.
De Boer won the Champions League with Ajax in 1995, beating AC Milan having a team dominated by Dutchmen whenever the utilization of players was restricted competitions.
The side then beat on home and off in the season’s competition, but Ajax’s win in Spain this week has been more striking, according to this former Netherlands forward.
“Now, if you are a team like Madrid and your rightback doesn’t perform the job, you buy the best rightback on the planet and will fulfill your team with 11 foreign players,” De Boer said.
“Ajax can also buy foreign players, but we stick with our doctrine and still managed to beat Real Madrid with so many youth players.”