Drogba, who turned 35 this month, will not play in the Ivorians' first game since a disappointing quarter-final exit at the recent African Cup of Nations, which was seen as the striker's last chance at a major trophy with his country.
Lamouchi told The Associated Press he didn't pick Drogba for Saturday's game because of concerns over the Galatasaray striker's fitness and form after his moves from Chelsea to China and then to Turkey.
The Ivorian team also needed a change of mindset after a string of failures in Africa despite being the continent's top-ranked team, the French coach said.
Drogba would have a place when he returned to form, Lamouchi said, but the striker is undoubtedly reaching the end of his time with his national team.
"Didier Drogba needs to work hard to get back to his best," Lamouchi said. "He needs to work to become the Drogba you knew before. That's why he's not among those I called for the match against Gambia."
Cote d'Ivoire leads its World Cup qualifying group but also has to start planning for Drogba's retirement. Lamouchi picked four home-based players in his squad for the Gambia qualifier, while leaving Drogba out.
The Ivorians - blessed with talent like Drogba, Toure brothers Yaya and Kolo and forward Gervinho - lost to eventual champion Nigeria at the African Cup in South Africa to continue a depressing run at the tournament.
"With this team I want more than respect, I want titles," said Lamouchi, whose own place as coach came in doubt after the loss to Nigeria in South Africa.