FORT MYERS, Fla. -- Rusney Castillo’s professional baseball career began at 12:05 p.m. Sunday on Field No. 1 at the Fenway South complex with a ground-ball single to left off a 20-year-old pitcher named Luis Cedeno.

Castillo, the Cuban defector signed by the Red Sox to a seven-year, $72.5 million contract earlier this month, was thrown out a minute or two later trying to steal second base in a Gulf Coast League playoff game against a team of New York Yankees minor leaguers.

Castillo, 27, followed it up 30 minutes later striking out on three pitches, all fastballs. In that at-bat, he swung and missed on the first pitch, fouled the next pitch back, then took a called third strike on a pitch on the outside corner.

That was the end of Castillo’s first professional game. He was the designated hitter, batted leadoff, wore No. 38 and played only three innings in the GCL playoff game.

It was the beginning of a process for Castillo, who hopes to play in Fenway Park before the end of the season.

While the game continued, Castillo and a translator met with reporters in the shade of JetBlue Park on a typically scorching Florida August day.

“I’ve wanted this day to come for a long time now,” Castillo, who doesn’t speak English, said through the translator.

It was his first baseball game since July 2013.

“I’ve done this for a long time,” Castillo said. “It’s like riding a bike. I’m happy. … Saw six pitches, got on base, was able to run around a little bit.”

The speedy center fielder was thrown out in the first inning on the steal with a headfirst slide.

“That’s my game,” Castillo said to several reporters as curious fans watched from a short distance away. “Get on and try to steal.”

Although he hasn’t played in a game in more than a year, Castillo is confident he’ll be able to proceed swiftly to Fenway Park. He’s not sure how many at-bats will be required before he feels ready to face big-league pitching.

His at-bats Sunday were against a pitcher who turned 20 in July. Cedeno, despite a 1-3 record in the GCL, has a 1.13 ERA and opponents have batted .161 against him.

“There’s no specific number of ABs,” Castillo said. “It’s a matter of just playing and we know the goal from the beginning has been to play in the big leagues this year.”

Castillo is eager to play a game in the outfield instead of being a DH. Between now and the end of the big-league season, he expects competition to make him better.

“I love to hit like any hitter loves to hit,” Castillo said.

He’s heartened by the success fellow Cuban players Yasiel Puig, Yoenis Cespedes and Jose Abreu are enjoying in the big leagues.

“It’s definitely added a lot of confidence,” Castillo said. “Motivates me. I want my countrymen to do well. … It’s definitely a motivating factor.”

When he arrives in Boston near the end of the season, Castillo expects to be the same player he’s always been.

“Try not to do too much and try to become somebody else,” Castillo said. “Another type of player I’m not.”

On Sunday, Castillo was an old-timer compared to many of his teammates and opponents. Every other Red Sox starter except 22-year-old right fielder Derek Miller is in his teens. Third baseman Rafael Devers is 17 and six of the starters are 18.

Although he was the oldest player on the field by a considerable margin, many Red Sox fans in attendance look on Castillo as part of the future, part of a chance to forget the miserable 2014 season and look ahead to better days.

Several dozen fans clustered in the bleachers around the field and peered through a chain-link fence, trying to catch a glimpse of the latest Cuban phenom playing his first game in a Red Sox uniform.

“This whole thing had a Woodstock, love-in feel to it,” said Red Sox fan Roy Kaplan, who drove a few miles from his Fort Myers home to watch the game.

Longtime fan Bob Maloney, who will turn 90 later this year and attended his first Red Sox game in 1935, also came out for the event. Despite the hype over Castillo, Maloney isn’t ready to anoint him the starting center fielder for Opening Day 2015.

“I’m going to have to see a lot more to put him ahead of Mookie Betts,” Maloney said.