It was only the second time the 20-year-old Cuban had pitched in a game situation for the Cubs, and if he was nervous, he wasn't showing it. Perhaps that's because two years ago he was the Serie Nacional Rookie of the Year for the Industriales, Fidel Castro's favorite team.
Four tosses later, including a three-pitch strikeout that ended when the batter took a curveball that broke over the outside corner, Concepcion walked back to his dugout at the back diamond at Fitch Park. He had retired the side with six pitches, working so efficiently that he could have been a pitching machine.
"That's who he is," said Oneri Fleita, the Cubs' vice president, player personnel. "That's exactly who he is."
Based on Concepcion's track record from Cuba and his showing in tryouts in the Dominican Republic, the Cubs committed $6 million over five years to sign him. The reality is, however, they do not know exactly who he is.
Because their scouts aren't allowed access to Cuba, major league teams never know as much about defectors as they do about the North American players they track from the time they are 15 or 16 years old. But since Tom Ricketts bought the Cubs and opened the spigot on funding for international signings, no team has collected more players from Cuba.
They had 10 Cubans in the minor leagues last season — four more than any other team, according to the website cubanball.com — and have added another wave of talented imports in the last six months. Everywhere you look around Fitch Park, there seems to be a talented Cuban, many with incredible work ethic.
"When the Cubs win the World Series, they are going to have a big Cuban flavor," said Jaime Torres, the longtime agent who represents Concepcion.
Or maybe, a few years from now, the Cuban invasion will have been only another dry well for the Cubs. Either way, you've got to give them credit for trying.
The Cubs finished as a runner-up to Oakland for center fielder Yoenis Cespedes, and continue to nervously await the chance to land Jorge Soler, a younger speed/power version of Cespedes who is having trouble getting his paperwork in order to be cleared to sign.
But the list of Cuban prospects who could arrive at Wrigley Field at some point in 2013, '14 or '15 is already long, thanks largely to the work of Fleita, special assistant Louie Eljaua and scout Jose Serra.
"We have a pretty good reputation there," Fleita said about Cuba. "We've treated guys the way we like to be treated. I like guys who have a hunger, who make sacrifices to play the game. I don't care where they're from. Our job is to give guys a chance to chase their dreams."
That's true in a broad sense, but Fleita isn't doing social work. He's helping stock a farm system that has been underfinanced and generally unsuccessful since a strong run in the 1980s, when the Tribune Co. was smart enough to hire Dallas Green and his posse, including scouting director Gordon Goldsberry.
A reduced big league payroll has made it possible to chase some big signings (Cespedes, Soler and Concepcion), but it's possible that the Cubs will benefit more from the strength-in-numbers approach.
The Cubs' Cuban buildup has largely been done largely in quiet but will be unveiled Friday at Space Coast Stadium in Viera, Fla. The Daytona Cubs, defending champions in the high-A Florida State League, will sprinkle several intriguing Cubans alongside more established prospects such as Matt Szczur and Ronald Torreyes.
-- Left-hander Frank Del Valle. Signed by the Cubs last summer, the 22-year-old is the Arthur Rhodes starter kit. He showed the poise often associated with Cuban players by not only rising to Daytona in his first pro season but throwing six scoreless innings in a championship series start three days after saving a must-win game in the league semifinals.
-- Second baseman-center fielder Rubi Silva. – Also 22, the left-handed hitter played alongside Dayan Viciedo, Jose Iglesias and Adeiny Hechavarria on Cuba's junior national team. He signed with the Cubs in December 2010 and hit .285 in his first pro season, split between low-A Peoria and Daytona.
-- Center fielder Elieser Bonne. He'll be 25 in his first North American season and comes without a Cuban pedigree. But he lit up a tryout last year with his athleticism and could provide the ultimate surprise after batting .313 in the Dominican Summer League.
The Cubans likely to stay in Arizona for extended spring training but have an impact later this season include:
-- Yasiel Balaquert. Built for power and blessed with a cannon arm, the former member of Cuba's junior national team was looking for a $10 million deal when he defected in 2010. He went unsigned for more than a year before taking a reported $400,000 from the Cubs.
-- Carlos Martinez. Arguably the greatest diamond in the rough in this crowd, the 6-foot-4, 215-pound right-hander was overmatching hitters with a mid-90s fastball and polished changeup in camp games. He will move fast if he can sustain that performance.
-- Yaniel Cabeza. A gifted catch-and-throw receiver, Cabeza was signed at the same time as Silva but has advanced more slowly as he masters English. He broke an ankle in the Instructional League and was behind in spring training.
Concepcion is also ticketed for extended spring training, since he didn't arrive in Mesa until March 11. He held his own as a 17- and 18-year-old at Cuba's highest level, but at age 20 will be developed cautiously.
Fleita says he looks at the Cuban lefty as if the Cubs had been given an extra first-round pick in the draft.
"He'd go somewhere in the top 15 picks in this country," he said. "Guys who throw strikes continue to throw strikes. Guys who you hope will throw strikes, sometimes they don't."