By Eric Radom (@ericfansfantasy)

Every year, there are several rookies that make their debuts after Opening Day and end up having a huge impact on your fantasy league. It is important to know what is going on down in the minor leagues, so that you are ready to pounce on any top prospect who is close to making an impact. At any point in the season, you may be struggling to find a lot of upside on the waiver wire, especially if you are in a deeper league. If you find yourself with an open bench spot and you do not like any of the available major league players, consider stashing one of these guys.

Last week's highlighted players were Nolan Arenado; Trevor Bauer; Mike Trout; Brad Peacock; and Jarrod Parker, who has already been called up by the Athletics.

Here are several players that have the talent and opportunity to make a fantasy impact this year:

1. Will Middlebrooks, Third Baseman, Red Sox  

Boston's No. 1 prospect, Will Middlebrooks is still expected to spend a full season at Triple A in 2012, after struggling during 16 games there to close out 2011. But he did hit .302, with 18 home runs and 80 RBIs during 96 games at Double A last year, and he has an advanced hitting approach at age 23, showing power to all fields. If there is one question about his development, it is his patience -- he had 95 strikeouts and 21 walks last year. Middlebrooks impressed in spring training and he is producing big numbers at Pawtucket through 19 games, with 17 runs, eight home runs, 25 RBIs, three stolen bases and a .375 average. Perhaps the most important stats are his 10 strikeouts and seven walks so far, showing he has improved his patience. He is blocked by Kevin Youkilis at third base right now, but there are several reasons that Middlebrooks still has a chance to make an impact this year. First, the injury-prone Youkilis has averaged only 120 games the last three seasons. In addition, the Red Sox are in deep trouble with their pitching and injury issues. I know it sounds crazy, but Youkilis is a free agent in 2013, and the Red Sox could decide to trade him this season to fill one of their other needs, knowing that Middlebrooks is ready to step in. Be ready to pounce on Middlebrooks if Youkilis or Adrian Gonzalez gets hurt.

2. Anthony Rizzo, First Baseman, Cubs

Anthony Rizzo was the main piece from the Red Sox in the Adrian Gonzalez trade two years ago. The Cubs acquired him this offseason for their top pitching prospect, Andrew Cashner. Rizzo is a big left-handed power hitter, so moving from Petco Park to Wrigley Field should help him. He struggled during a short stint with the Padres last year, showing he still needs to shore up some holes in his long, powerful stroke. The Cubs decided to give a late-blooming prospect, Bryan Lahair, the first base job this season, and they have vowed not to rush 22-year-old Rizzo. The problem with that plan is that Rizzo appears to be too good for Triple A. After hitting .331 with 26 home runs and 101 RBIs last year during 93 games, he has continued his dominance this year, hitting .373 with seven home runs and 19 RBIs during 19 games. The Cubs are not built to win this year, so they will have no reason to hold him back if he continues this pace. Bryan Lahair may appear to be a block with his hot start, but he could move to left field if and when the Cubs trade Alfonso Soriano, who is off to a terrible start. Pay attention to the Cubs this season, because they also have a center field prospect worth mentioning in Brett Jackson.

3. Garrett Richards, Starting Pitcher, Angels

The Angels were close to using Garrett Richards as their fifth starter to start the season, after he impressed during spring training. But veteran Jerome Williams was able to return from a hamstring injury just in time to claim the job. Williams hasn't had any long stays in the big leagues, so it is only a matter of time before Richards gets a chance, especially if he continues to dominate Triple A to the tune of three wins, zero losses, 27 innings, 27 strikeouts, six walks, 1.67 ERA and a 0.96 WHIP. Although Richards has been overshadowed by other pitching prospects, he may be one of the most major league-ready. He features a mid-90s sinker, a four-seamer that can reach the upper 90s, a solid 12-6 curveball, and an above-average slider. He has also shown good control and the ability to go deep into games. Although the Angels are struggling now, Richards will offer great win potential should Williams, or any of their top four starters, suffer an injury.

4. Bryce Harper, Outfield, Nationals

At age 19, Bryce Harper is one of the most talented prospects to come around in quite some time, and there is no doubt he should have an impact this season. The only question is when. Since the Nationals sent him to Triple A to work on becoming a center fielder, he has struggled a bit, batting .234 with only one home run and one stolen base. He should have no problem turning it around though, so make sure to get him on your roster in deeper leagues if you have a spot. The Nationals are looking to contend this year, and their center field situation is their biggest question mark. Roger Bernadina has been awful so far, and Rick Ankiel has hit in the .230s each of the last three years. The pressure will mount as the season progresses for the Nationals to bring up Harper, so it is only a matter of time.

And, for a bonus:

Billy Hamilton, Shortstop, Reds

Although he is probably a year or two away from reaching the majors, Billy Hamilton is one of the most exciting prospects in all of baseball. Hamilton actually makes Dee Gordon look slow, if that is even possible. Hamilton stole 103 bases at low Class A last year in 135 games, and he has been even better in high Class A this year, adding some power to his game as well. So far, in 2012, Hamilton is hitting .356 and slugging .589, with one home run and 19 stolen bases during 19 games. At this pace, he will easily break 100 stolen bases again. Fantasy managers all over are dreaming about this guy, but they will have to wait until at least 2013 to experience that dream.

Posted April 25, 2012