Seibu Lions announced on April 18 that it has signed Jorge Gonzalez pitcher and Ronnie Oliver pitcher from the Dominican Republic to developmental contracts. number are 144 for Gonzalez and 145 for Oliver.

"I am fortunate to have had the opportunity to play for The Lions and grow as a player, and I will do my best with the desire to contribute to win as a key player in the team," said Gonzalez, a 198 cm and 116 kg right-hander, who has a fastball of over 150 km. Hiroike, general manager of the team, said, "The charm is that he makes use of his large physique and throws down fastball that exceeds 150 kg at any pitcher time, and he is a power type that interweaves slider and sinker around fastball to closer hitter."

Oliver is a right-handed pitcher with an impressive physique of 193 cm and 85 kg, who throws fastball exceeding 150 km/h, curves, slider, and change-up. Team general manager Hiroike said, "We believe he is capable of pitching long inning, but we will assess his role and suitability after he joins the team," indicating that the plan is to give him practical experience first. Oliver stated his goal, saying, "I want to contribute to the team and continue to grow by working hard every day, without forgetting humility and a dedicated attitude."