The 27-year-old Cuban right-hander defected during a tournament in Europe last summer, established residency in Spain and began working out in Mexico. The native of Havana played professionally for the Havana Industriales of Cuba's Serie Nacional for eight seasons, posting a 61-43 record with a 3.55 ERA, 684 strikeouts and 390 walks in 213 games.
Despaigne agreed to a Minor League deal and a $1 million signing bonus in May after completing a physical and obtaining a work visa in April. He will be making his debut as he takes the spot of the injured Andrew Cashner, who landed on the disabled list Monday with a sore right shoulder.
"Overall, even though his ERA is high, his ability to make pitches and the composure he has from where he's been will help," said Padres manager Bud Black. "His arm feels good, he's ready to go and he's excited."
Despaigne began his Minor League career with two Double-A starts, posting a 1.17 ERA. He then was promoted to Triple-A, where he went 1-3 with a 7.61 ERA in five starts.
In Despaigne's most recent start, Wednesday against Iowa, he allowed three runs in five innings and finished with seven strikeouts. In his two stops combined, he has 41 strikeouts in 31 1/3 innings.
"He threw well in his two starts for San Antonio, mixing all of his pitches from varied arm angles," Randy Smith, the Padres' vice president of player development, said last month. "We felt that he was ready for another challenge against more experienced hitters."
The Padres have watched Despaigne for a while, including his workout at the team's facility in Arizona during Spring Training.
Despaigne has drawn comparisons with former big league pitcher -- and fellow Cuban -- Orlando Hernandez in terms of his wide variety of pitches and arm angles.
"Odrisamer is experienced and savvy enough that he will be able to adjust to hitters at the next level," Smith said. "He's a fun guy to watch, as he throws everything except the kitchen sink, and he may have thrown that, too."
Black was curious to see Despaigne.
"It's going to be a wide variety of pitches from a wide variety of angles," he said.
In order to make room for Despaigne on the 40-man roster, the Padres moved pitcher Casey Kelly to the 60-day disabled list.
Kelly, working his way back from Tommy John surgery in 2013, was placed on the DL on March 29. He made two Minor League rehab starts in May but hasn't appeared in a game since May 19 due to soreness in the elbow. He's to resume throwing in 10 to 14 days.