Costa Rica will be hoping to build on their impressive 2014 World Cup campaign in Brazil, qualifying from a group which contained Uruguay, Italy and England before reaching the quarter-finals.
Ramirez has to confirm his final 23-man squad on June 4, with Costa Rica set to face Serbia, Brazil and Switzerland in Group E of the 2018 tournament.
Squad in full:
Goalkeepers: Keylor Navas (Real Madrid, Spain), Patrick Pemberton (Liga Deportiva Alajuelense), Leonel Moreira (Herediano)
Defenders: Cristian Gamboa (Celtic, Scotland), Ian Smith (Norrkoping, Sweden), Ronald Matarrita (New York City, USA), Bryan Oviedo (Sunderland, England), Oscar Duarte (Espanyol, Spain), Giancarlo Gonzalez (Bologna, Italy), Francisco Calvo (Minnesota United, USA), Kendall Waston (Vancouver Whitecaps, Canada), Johnny Acosta (Aguilas Dorados, Colombia)
Midfielders: David Guzman (Portland Timbers, USA), Yeltsin Tejeda (Lausanne-Sport, Switzerland), Celso Borges (Deportivo La Coruna, Spain), Randall Azofeifa (Herediano), Rodney Wallace (New York City, USA), Bryan Ruiz (Sporting CP, Portugal), Daniel Colindres (Saprissa), Christian Bolanos (Saprissa)
Forwards: Johan Venegas (Saprissa), Joel Campbell (Real Betis, Spain), Marco Urena (LAFC, USA)