Martinez agreed to terms on a signing bonus worth $2.5 million over the weekend with the Giants and later changed his mind. The deal, which the Giants did not confirm, was pending a physical. Sources told MLB.com that Martinez's father was seeking a bonus closer to $3 million.
The 6-foot-2, 195-pound Martinez is ranked No. 4 on MLB.com's Top 30 International Prospect list.
Martinez, 20, was among the first Cuban players eligible to sign during the international signing period. However, he later found himself in a competition for attention with top Cuban prospects like outfielder Yusnier Diaz, 18, and Vladimir Gutierrez, 19, and others who entered the market in search of deals with Major League teams. Martinez left Cuba in November, established residency in Haiti in February and has been training in the Dominican Republic.
The right-handed hitting Martinez has a quick and compact power stroke. He's shown the ability to hit home runs to all fields and work the count. He's speedy out of the box and shows base-stealing potential. He has also shown good instincts on defense and the ability to cover the gaps in the outfield. Those skills combined with a playable and accurate arm could mean he should stay in center field as he develops.
The outfielder played for Cuba's junior national teams in Mexico and Venezuela and spent two seasons with Las Tunas in Cuba's Serie Nacional, the island's top league.
Martinez is set to join a class of top international prospects for the Cubs that includes shortstop Yonathan Perlaza, ranked No. 15; outfielder Yonathan Sierra Estiwal, ranked No. 18; shortstop Aramis Ademan, ranked No. 21; and Panamanian catcher Miguel Amaya, ranked No. 26.
Jesse Sanchez is a national reporter for MLB.com. Follow him on Twitter @JesseSanchezMLB. This story was not subject to the approval of Major League Baseball or its clubs.