The Padres are considered the favorite to sign Ona, who enters MLB Pipeline's Top 30 International Prospects List at No. 8.
Ona, who left Cuba last July, has a muscular and projectable body. He has shown the ability to hit for power and is developing into a well-rounded overall hitter. Ona has already shown a polished approach in the batter's box.
On defense, the teenager has displayed a good arm and the ability to play all three outfield positions. That said, Ona's overall skill set might make him best suited for a corner spot. His track record includes games in Cuba's Junior National Leagues and the COPABE 18U Pan American Championship in 2014.
The Padres have already signed 27 international prospects since the international signing period began on July 2, a list that includes Cuban left-hander Adrian Morejon, ranked No. 2, for $11 million. The club also signed shortstop Luis Almanzar, ranked No. 4, to a $4 million deal; shortstop Gabriel Arias, ranked No. 6, for $1.9 million; outfielder Jeisson Rosario, ranked No. 11, for $1.85 million; shortstop Jordy Barley, ranked No. 17, for $1 million; shortstop Justin Lopez, ranked No. 29, for $1.2 million; and Mexican outfielder Tirso Ornelas, ranked No. 30, for $1.5 million.
The Padres added catcher Alison Quintero for $830,000, along with right-handed pitchers Michel Miliano for $450,000 and Jose Manuel Guzman for $400,000. The club added infielder Tucupita Marcano, who signed for $320,000. San Diego also signed Taiwanese right-hander Wen-Hua Sung for $675,000 on July 3.
The Padres are already facing the most severe penalty for exceeding their pool by 15 percent or more, so they will not be allowed to sign a player for more than $300,000 during the next two signing periods. They must pay a 100 percent tax on the pool overage, a total close to $43 million.