Martinez has played 19-year-old Ross Barkley in each of the Merseyside club's nine Premier League games so far this season, but the Spaniard feels that many youngsters fail to make to grade because they fall into a comfort zone.
The former Wigan Athletic manager told BBC Radio 5 live: "The way that we develop players up to the age of 18 is the best in the world. Sometimes [it is] too good in certain aspects, because we've got absolutely every single facility.
"From that point on, the environment is not challenging enough to prepare our youngster.
"The boys need to go out on loan first-team football out of their environment to get them ready."
Everton host Tottenham Hostpur at Goodison Park tomorrow.