Prospects are an essential part of any keeper or dynasty league. Keep in mind - they are also a valuable commodity in re-draft leagues if you have a keen awareness of which prospect's value is on the rise and can make an immediate fantasy impact once he gets the call.

This week's edition of the RotoBaller Stock Watch takes a look at five prospects whose respective fantasy value is on the rise. Fantasy owners should be wary and consider stashing these potential breakout candidates on their benches.

Editor’s Note: to read about even more MLB prospects, rookies and potential call-ups, be sure to check out our MLB prospects for fantasy baseball homepage which has lots of great weekly analysis.

Gallo is scorching hot at the plate right now, smashing four home runs in the last five games, including an inside-the-park HR. Gallo is slashing an astonishing .341/.457/.718 with seven dingers and one steal in 85 AB with Double-A Frisco. Within the last week, the Rangers have elected to move Gallo to the outfield, which should only expedite his timeline to the Majors. He’s not going to take over for Gold Glove caliber third baseman Adrian Beltre anytime soon. But, given the lack of depth in the Texas outfield, he could make an immediate impact on the green this summer.

The 6'5" behemoth has blasted 40 home runs in each of the previous two seasons and possesses more power than any prospect in the game now. The strikeouts are a major concern with Gallo. If he proves he can handle advanced Triple-A pitchers later this summer, he could get an opportunity in Arlington this year. He’s a must-own fantasy prospect with a ceiling that is unlike any other in the game.

Blake Snell, SP, Tampa Bay Rays

The most fascinating storyline in baseball that nobody seems to be talking about is Snell’s incredible scoreless streak, which he increased to 46 innings earlier this week. The southpaw is striking out over a batter per inning (9.72 K/9) while nearly cutting his walk rate in half (2.88 BB/9) at Double-A. The former 2011 1st Round pick has taken a few years to develop; but if he keeps pitching like this, especially once he is promoted to Triple-A, he has a chance to make it to the big leagues later this season.

My affinity for fellow Rays pitching prospect Brent Honeywell is well documented. Still, Snell has a chance to surge past him as the top pitching prospect in the organization. With a low-90’s fastball, solid changeup and slider, Snell profiles as a solid back of the rotation starter. If he continues to improve his command, his ceiling will rise. Snell’s stock has risen more than any other pitching prospect in the game this spring and he needs to be on mainstream fantasy owners' radars.

Widely considered the top shortstop prospect in the game, Correa has obliterated minor league pitching this spring. He's slashed .385/.459/.726 with seven home runs and 15 stolen bases in 29 games at Double-A before earning a promotion to Triple-A. In eight games since the promotion, Correa is hitting .316/.357/.500 with a home run and one steal.

Correa doesn’t have much left to prove in the minors and it seems like only a matter of time before the Houston Astros top prospect is with the big-league club for good. With Opening Day starter Jed Lowrie currently on the disabled list with a thumb injury and the (not so) dynamic duo of Marwin Gonzalez and Jonathan Villar holding down the position, there isn’t much standing between Correa and everyday at-bats. It’s safe to say that Lowrie is not the long-term answer at the position, even if he comes back healthy.

What makes Correa such a fascinating prospect, even in re-draft leagues, is that he can impact so many categories from a fantasy perspective right out of the gate. Middle infielders who possess the ability to hit for both power and steal bases are a rarity in the game today. Finding one who is just 20 years-old is even more rare. It’s not a stretch to think that Correa will be up at some point this summer, especially if the Astros have a shot at making the playoffs.

One of the elite defensive shortstops in the minors, the Indians elected to let Lindor’s bat get some additional seasoning in Triple-A despite the fact that his defense is big-league ready right now. He’s responded in a big way, slashing .261/.335/.373 while increasing his walk rate and cutting down his strikeout rate.

Reports out of Cleveland indicate that Lindor isn’t close to joining the Indians anytime soon, but the 21-year-old phenom could certainly get the call later in the year. He’s likely owned in all dynasty formats, but he is worth stashing in deeper re-draft leagues in the event that an injury to either Jose Ramirez or Jason Kipnis opens up an opportunity for him. Lindor doesn’t possess much power, but he is an excellent contact hitter with the speed to provide an immediate fantasy impact on the base paths.

Jonathan Singleton, 1B, Houston Astros

You might remember Singleton from his less than spectacular debut, in which he hit an abysmal .168 over 362 plate appearances last summer. He’s not back with the Astros just yet, but after a week in which he was named the Pacific Coast League Player of the Week after hitting .357 with five home runs, 23 RBI and a pair of stolen bases, he might not be far off from getting another opportunity.

The biggest obstacle for Singleton will be finding at-bats with the Astros. Assuming he’s playing first base, that move would relegate Chris Carter to designated hitter and force Evan Gattis into the field. He doesn’t profile as a potential fantasy superstar like some of the names on this list, but considering where his stock was at the end of last season, he’s risen a lot in a short time period to become relevant again.