FORT MYERS, Fla. — It all happened in an instant.

Ryan Kalish was on first base when Marco Scutaro hit an infield single to third. The throw to first was bobbled, and so the young outfielder did not hesitate. Kalish rounded second hard, picked up the ball and raced into third, well ahead of the throw back across the diamond.

It was not the sort of thing that would add to the statistical resume of one of the Sox’ top prospects. But the play offered a glimpse into the core of who Kalish is as a player.

“I’m pretty crazy. I’m super aggressive. I really, really like to get out there and have some fun,” said Kalish, who is spending his first full spring in big league camp after a few one-day cameos in camp in 2009. “Shoot, last year I think I stole third with two outs in a big league game. Tito was like, ‘Man, you better get there. If you get out there, I’m going to be on you.’

“He just said we really want you to be aggressive, kind of cut-throat. I’m just taking my aggression out on the paths. It’s fun.”

It was the sort of play that tends to capture the attention of onlookers, particularly the decision-makers in an organization. The simple burst showed a player with good baseball instincts and on-field awareness, as well as the athleticism and speed to take advantage of a bobble.

It is one thing to have tools. But Kalish has both natural ability and an understanding of how to apply it. As such, he typically endears himself to those for whom he plays. Sox manager Terry Francona counts himself among the Kalish fans.

“Wherever he plays, he’ll be one of the manager and coaches’ favorite guys. You can’t help it,” Francona said. “He’s like an animal right there. Great kid. He’s going to get every last bit out of his talent, and it looks like he’s got a lot of talent. So that’s good. That’s the type of player he is. When you saw him go first to third, that’s what we heard about in our [organizational] meetings.”

Such impressions are a major component of Kalish’s ambitions for the spring. While some prospects can become shy or retiring both in the clubhouse and on the field while trying to fit into big league camp, the 21-year-old understands that he cannot have a successful spring if he tempers his on-field personality.

“I’m here to make an impression on people who are higher up. Hopefully, when I get a chance to be up here, guys will say, ‘Wow, he plays hard,’” said Kalish, who made a solid impression in camp last year when he lined a triple to deep left-center off Reds closer Francisco Cordero and made a diving catch that earned him a SportsCenter highlight. “My goals are just make a good impression, play hard and make people like me, so if I get called up, they believe I can be able to help the team win.”

At the same time, while trying to make an impression, Kalish is also trying to absorb as much as he can. He is tracking how the Sox’ major leaguers conduct themselves in hopes of finding ways to advance his performance.

In 2009, he made significant offensive strides. Fully recovered from the surgery to repair a broken hamate that he had in late-2007, he showed power that had previously not been evident in games.

After hitting .273/.365/.363/.727 with five homers in 2008, he hit .279/.364/.457/.820 with 18 homers while splitting his year between High-A Salem and Double-A Portland.

Most of his homers in 2009 came when the left-handed Kalish pulled the ball to right. This spring, he has been making a conscious effort to dedicate part of his time in batting practice to driving the ball to the opposite field.

“The power starts on the pull side. It’s been kind of a natural progression of letting the ball get to the point where I can drive it to the opposite field,” Kalish said. “I’ve been really watching [Dustin] Pedroia and [Kevin] Youkilis, how they really have a plan of attack.

“Letting the ball get deep is part of their everyday routine. I try to incorporate that with my stuff. I’ve definitely worked hard to get stronger. Why not incorporate that the other way as well as to the pull side?”

Of course, Kalish is also monitoring other aspects of how Pedroia and Youkilis conduct themselves. The two players carry themselves with abandon on the field. In their intensity, Kalish believes that he sees kindred spirits whom he can use for inspiration.

“Just seeing how they are around here, the aggression they have out there, it’s been really fun to watch,” Kalish said. “Hopefully, I’ll be able to do it right next to them some day.”