It was in a Gulf Coast League playoff game that the Cuban outfielder played his first baseball game since signing a seven-year, $72.5 million deal with the Red Sox on Aug. 23. In fact, it was the first time Castillo played in any baseball game in over a year.
Three pitches into his professional career in the United States, Castillo turned on a 2-0 pitch from Yankees Minor Leaguer Luis Cedeno and hammered it into left field for a single.
"I feel great," Castillo said through an interpreter. "It was a good day. I've wanted this day to come for a long time now. It finally got here. I feel good physically and mentally."
Moments later, Castillo, who is known for his speed, bolted for second but was caught stealing.
It didn't take long for him to get back in the flow of being a baseball player.
"That's my game," said Castillo. "Try to get on and try to steal. It was something I was definitely thinking about."
Castillo seemed unfazed by getting a hit following such a layoff.
"I've done this for a long time," said Castillo. "It's like riding a bike. I felt good and I was happy I was back out there today."
Castillo served as the designated hitter in his debut and struck out looking in his second at-bat.
There have been various estimates about when Castillo played his last game before he was suspended for trying to defect from Cuba. When asked Sunday, Castillo estimated it was July 2013.
On Monday, Castillo will play at one of the club's Minor League affiliates, though the Red Sox haven't announced which one yet.
Perhaps the most intriguing development left in the 2014 season for the Red Sox will be when Castillo gets called up to the Majors. The outfielder is keeping an open mind as far as how many at-bats he needs before making that step.
"There's no specific number of [at-bats]," said Castillo. "I's a matter of just playing, and the goal from the beginning for me is to play in the big leagues this year."
Of late, Cuba has been a pipeline for successful Major League players such as Aroldis Chapman, Yasiel Puig, Jose Abreu and Red Sox slugger Yoenis Cespedes.
"It's definitely added a lot of confidence, it's definitely motivated me," said Castillo. "I want my countrymen to do well -- guys that I played with. It's definitely a motivating factor and something that's assisted me with my confidence level."
But Castillo won't try to follow in the footsteps of those players as much as he will try to create his own.
"My No. 1 objective would be to be the same player I've always been," said Castillo. "Play my game and not try to do too much or try to become someone else -- another type of player I'm not."