Charter airline Condor issued a statement saying three other crew members on the flight from Hamburg to Gran Canaria indicated they felt unwell after noticing a funny smell on the aircraft, The Local.es reported Tuesday.
The airline said none of the 242 charter passengers complained that anything was wrong.
Two crew members passed out briefly when the plane's engines were restarted Friday after all the passengers had disembarked, the airline said.
A different aircraft will be used to fly passengers back to Germany.
Condor said it is cooperating with Spanish authorities to investigate the incident.