Here is the list as of today all Astros org players who are on winter ball rosters. 

Mexican Pacific League

Dennis Sarfate

Venezuelan Winter League

Kyle Middleton – Tigres
Juan Gutierrez – Leones
Cesar Quintero -Leones
Victor Garate – Leones
Fernando Nieve – Caribes – on the DL
German Melendez – Magallanes
Marc Saccomanno – Magallanes
Wlad Sutil – Magallanes
Frankie Caraballo – Magallanes
Luke Scott – Magallanes
Paul Estrada – Magallanes
Hector Gimenez – Magallanes
Felipe Paulino – Bravos de Margarita
Enyelbert Soto – Bravos de Margarita
Humberto Quintero – Aguiles de Zulila

Dominican Winter League

Sergio Severino – Aguiles Cibaenes
Phillip Barzilla – Licey
Sammy Gervacio – Licey – Now on roster
Polin Trinidad – Licey
Yordany Ramirez – Licey
Ronnie Martinez – Estrellas Not on opening day roster, also reported to be using name Ronnie Ventura by a BA transaction/MILB.com player page.
Miguel Asencio – Estrellas
Santo Luis – Estrellas
Osvaldo Fernando – Estrellas
Jhon Florentino – Gigantes

Hawaiian Winter League
North Shore Honu
Bud Norris
Chris Johnson – Left due to Injury/Personal Reasons per HWB web site
Billy Hart – took Johnson’s spot
Lou Santangelo
Sean Walker

Arizona Fall League – Mesa Solar Sox

Brad James
Josh Muecke
Chad Reineke
J.R. Towles – Taken off roster due to getting enough work during Sept. call up.
Tommy Manzella
Josh Flores
Mitch Einertson