The former West Indies Test star took over the job of the national coach in January with the hope of turning Kenyan cricket round after two years of internal upheaveal and the intention of establishing a framework for the future.
But he said it was not enough for Kenya to play in limited overs cricket only but there was need for the introduction of two-to-three day matches for the players to get used to the longer version of the game.
"There is no doubt that there is a lot of talent in Kenya," said Harper at an awards ceremony to honour the Nairobi provincial cricket league winners Saturday night.
He acknowledged the tough challenge he faces in motivating his players for the 2007 World Cup in his native West Indies, only four years after reaching the semi-finals of the last event in South Africa.
"It is not enough to have the talent alone," he said. "A lot of work has to be done."
"Kenya has to show it is the best associate member both in the short and long version of the game and unless the players get used to playing longer cricket, it will be difficult to compete at the international level."
The 42-year-old Guyanese has already led the team to two international tours of Zimbabwe and Bangladesh and in the drawn ICC Intercontinental Cup match against Holland in Nairobi.