BRADENTON, Fla. -- If Yoan Moncada looks more like a linebacker than a second baseman, his muscular frame doesn't deter his quickness or ability to cover all the ground his job entails.
Right-hander Joe Kelly and his teammates learned that first-hand on Wednesday, when MLBPipeline.com's top-rated Red Sox prospect (No. 7 overall) took the bus ride to Bradenton and made his Grapefruit League debut in Boston's 6-2 victory over the Pirates.
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Moncada went 0-for-2 with a walk and scored a run. But on this day, he made his mark with athleticism on defense. Starting at second base, Moncada made two nice plays with the glove while also looking smooth in turning two double plays.
Ever since the Red Sox made the $31.5 million investment to win the Moncada sweepstakes a year ago, his position has been looked at skeptically.
Perhaps this is because veteran second baseman and leader Dustin Pedroia is signed through 2021. Or maybe it's because Moncada is such a gifted athlete that he looks like he could play just about anywhere on the diamond.

Kelly was candid enough to admit his preconceived notion that Moncada's size (6-2, 220 pounds) wouldn't lend itself to second base.
"I work out in the offseason with NFL players -- [wide receiver] Marvin Jones, receivers, defensive backs, combine guys going in," said Kelly. "I see NFL players every day, and he's bigger and stronger than all the NFL guys. It's ridiculous. Before I ever saw him play, I'd be like, 'There's no way. He's going to move to the outfield one day.'
"Out of like lateral movements, I would have figured he's like 5 out of 10. It turns out he's like a 9 out of 10. He was explosive today. It was pretty fun to watch, honestly."
It started on the first play of Wednesday's game while Kelly and the Red Sox were on defense. Pirates leadoff man Alen Hanson dropped down a bunt that skipped past Kelly. And in came Moncada with closing speed and a quick transfer to first to nail the runner by a step.
"I underestimated him big time," said Kelly. "He's quicker than I thought. Just because of how big he was, I was like, on plays like that [bunt play], just in my head I was like, 'There's no way he could get to them.' And then the guy put down a swinging drag bunt, I just barely missed it, and he was there.
"Then I saw him flip a ball and saw him get one up the middle. His range and his explosive quickness, like I said, I just underestimated him. It's just way better than I imagined just because he had so much mass on his body that I just didn't figure he'd move like that."
Those who watched Moncada play for Class A Greenville last year know all about the speed. Moncada stole 49 bases in 52 attempts, an outlandish success rate.
He beamed when told by a reporter that Kelly and other Red Sox players were impressed by his speed.
"That makes me happy to hear," Moncada said through an interpreter. "I'm honored my teammates think that way of me. I thank them for the opportunity to be here and play for them and take their advice, and it's just a blessing to be here in this organization."
The Red Sox had Moncada play exclusively at second base last season, and the club hasn't revealed any plans to change that approach in 2016, though it certainly could happen at some point.
"It all depends on what the team wants from me and if they desire me to play in the outfield, then I'm happy to do that," Moncada said. "But I don't see a change in positions coming. I think with this team, I'll be second base for quite a while. If they want me to move to the outfield and that's what they want, that's what I'll do."
The 20-year-old Moncada is not in Major League camp, but the Red Sox are giving him cameos when they can. This was the second look, following a 2-for-2 performance against Northeastern University on Feb. 29.
"I felt good playing with those guys, playing against actual Major League competition, and it just felt good to be out there and starting," said Moncada.
He faced quality competition from the mound in Ryan Vogelsong, Mark Melancon and Arquimedes Caminero. Moncada was at his best against Caminero, falling behind in the count 1-2 before working an eight-pitch walk.
"He's facing someone who's mid to upper 90s with a good late breaking ball, and he showed patience to stay within the strike zone," Red Sox manager John Farrell said. "He didn't expand. Typically, you see a guy with that high of a velocity, sometimes guys have to start their swing earlier. It tells you he's seeing the ball well."