Bolt, winner of six Olympic gold medals, will earn an estimated $10 million (6 million pounds) a year in a sponsorship deal with German sportswear company Puma that will take the 27-year-old to the end of his career.
El Guerrouj told Reuters on Tuesday that endorsements and support for runners at longer distances were much less.
He said youngsters were also being lured away from athletics to other sports which was a problem the International Association of Athletics Federations (IAAF) had to solve.
"Usain Bolt is doing a great job for track and field, but he's casting a shadow over other races, which is very hard for those athletes, so it's the role of the IAAF to promote these to be more in the limelight," El Guerrouj said.
"We have some good athletes in some different middle distance races, but in general the youth is more interested in doing different sports like soccer, tennis."
The Moroccan, who also holds the world mile record, said some local and foreign companies had sponsored him during his career, but these contracts were small change compared to the endorsements earned by football players Cristiano Ronaldo and Lionel Messi.
Doping allegations have sullied athletics of late, with several athletes failing drugs tests. They include Bolt's Jamaican team mates former world 100 metres record holder Asafa Powell and twice 200 metres Olympic champion Veronica Campbell-Brown.
"A zero tolerance rule must be in the sport, we are promoting Olympic sports and they must be clean," double Olympic champion Guerrouj said.
"It's hard to talk about track and field today, there some issues we need to fix."
(Reporting by Matt Smith; Editing by John Mehaffey)
