3B Vinnie Catricala
Baseball America has him rated as the ninth best prospect in the Seattle system, and the hitter with the best strike zone discipline. He displayed average power potential, at least for a corner infielder, until this past season, when he broke out for 25 home runs, 106 RBI, 17 steals and a .349 average in 133 games between high-A and double-A. He was named the Mariners Minor League Player of the Year in 2011. Catricala has had an average start to the 2012 season, hitting 7-for-28 with no homers, one steal and no walks.
RHP Chance Ruffin
Selected by Detroit in the first round of the 2010 draft, Ruffin was one of the key components of the mid-season trade that sent Doug Fister to Detroit. Baseball America has him rated as the seventh best prospect, and the one with the best slider, in the Seattle organization. He has future MLB closer written all over him. Ruffin appeared in 44 games between double-A Erie and triple-A Toledo last season, saving 19 games and posting a 2.03 ERA, while striking out 60 in 48 2/3 innings. He is off to a strong start this year, albeit in a small sample size. Ruffin has appeared in two games, throwing three innings total. He has allowed only one baserunner in those three innings, striking out three and picking up a save.
RHP Forrest Snow
The big righty didn't have a good start to the season. After a dominant 2010 season spent in the bullpen, where he gave up only three runs in 45 1/3 innings, he transitioned to the starting rotation in 2011, to mixed results. At three levels of the minors last season, he appeared in 28 games with 21 starts. Snow combined to go 5-12 in those games, with a 5.09 ERA. However, he showed decent command of the strike zone, striking out 127 batters and walking 42. Snow gave up four runs in five innings, walking five batters, in his 2012 season debut.
LHP Oliver Perez
While no longer a prospect, there haven't been too many more disappointing players than Oliver Perez the past couple of seasons. A former top prospect with Pittsburgh, Perez was never able to establish good control in the major leagues. He signed a three year, $36 million contract with the Mets prior to the 2009 season, a deal he was released from in March 2011 after posting a 6.80 ERA in 17 appearances with the Mets in 2010. He spent 2011 pitching at double-A Harrisburg, where he posted a 3.09 ERA in 16 appearances, 15 of them starts. Perez has been pitching out of the bullpen for the Rainiers so far this season, giving up two runs on four hits and two walks in 4 1/3 innings.