You see it in their numbers, in their eyes or in the way talent evaluators gush about their abilities.

Some ballplayers are bound for glory, it seems. And some years the time feels right and the player looks ripe to break out in a big way.

"All you can do," said Diamondbacks right fielder Justin Upton, "is prepare yourself for that big year."

As we count down to Opening Day on March 31, MLB.com will identify Five To Watch in various categories -- from big names looking to get healthy to big prospects looking to crack the roster to those with big question marks looking to get their acts together.

To begin, here are five players who appear primed to take a big leap forward this season. These are players who have had accomplishments but can raise themselves to superstar status in the coming six months.

5 to watch
• Ready to leap to stardom
• Staying healthy vital
• Bash or crash
• Wondering about
• Get it together
• Make an impact
• Can't wait to see
• Rake or break

Buster Posey, C, Giants

To think, earning Rookie of the Year honors while catching and batting cleanup for the world champions was only the beginning for Posey. Could an MVP trophy be next?

It's not inconceivable, given Posey's natural talent and calm-under-pressure mentality. He has poise, and he has power to all fields. Furthermore, he couples those skills with the defensive acumen to call games for what was baseball's strongest starting staff in 2010. Posey hit .305 with an .862 OPS, 18 homers, 23 doubles and 67 RBIs in 108 games last season. He turns 24 next week. He's only just begun.

Colby Rasmus, CF, Cardinals

Rasmus has already improved his once-testy relationship with manager Tony La Russa. His next step is to improve his consistency. If he does, he could be one of the more dynamic center fielders in the game. Last year, he hit .276 with an .859 OPS (132 OPS+), 23 homers, 28 doubles and 66 RBIs. Those were respectable numbers, no matter how streaky the path taken to get to them.

La Russa appears likely to bat Rasmus in the No. 2 spot in the order, which will hurt Rasmus' run production (and he certainly has the power to slot lower) but should make him a reliable table-setter for Albert Pujols and Matt Holliday.

Carlos Santana, C, Indians

The last time the Indians had a switch-hitting catcher with a sweet swing, it worked out pretty well. His name was Victor Martinez. Santana once idolized Martinez, but he has the skill to perhaps have even more of an impact at the Major League level because of his power and plate discipline.

The Indians got a taste of what Santana can contribute after they called him up in June, and he hit .345 with a 1.165 OPS in his first 18 games. The league adjusted to him in July, but before Santana could be given reasonable time to readjust, his season ended on a vicious home-plate collision at Fenway Park. Now he's healthy and ready to show everybody what the fuss is all about.

Justin Upton, OF, Diamondbacks

As the first overall pick in the 2005 Draft, Upton has been in the public consciousness for so long that it's easy to forget he's only 23 years old. He is, in fact, five months younger than Posey.

So while Upton hasn't yet lived up to expectations, aside from a strong 2009 season, he is young and talented enough to suggest the best is yet to come. First and foremost, Upton must stay healthy. He's never appeared in more than 138 games in a season. Last year, he hit .273 with 17 homers, 27 doubles and 69 RBIs and was the subject of rampant trade rumors. But the D-backs kept him, and they have seen improvement in his swing this spring.

Matt Wieters, C, Orioles

Already, terms like "overrated" and "disappointing" have been floated on the interwebs in describing Wieters. Perhaps that comes with the territory, given the hype bestowed upon him after the Orioles made him the fifth overall pick in the 2007 Draft.

But it seems a bit unfair, given that Wieters is just 24. The Orioles' coaches have been raving about his improved conditioning and clubhouse presence this spring, and there were reasons why Wieters was so hyped in the first place. In 2010, his first full season, he hit .249 with 11 homers and 55 RBIs, which was, indeed, a disappointment. But as Wieters matures, don't rule out the possibility of a breakout.

Others ready to leap: Pirates third baseman Pedro Alvarez, Royals first baseman Billy Butler, Reds right fielder Jay Bruce, Cubs shortstop Starlin Castro, Dodgers right fielder Andre Ethier, Brewers starter Yovani Gallardo, Braves right fielder Jason Heyward, Tigers center fielder Austin Jackson, Jays starter Brandon Morrow, Astros right fielder Hunter Pence and Brewers second baseman Rickie Weeks.