In Seattle, all eyes are (justfiably) always on Felix Hernandez. He's one of the best pitchers in baseball, he's close to agreeing to a huge contract extension with the team, and he's the face of the franchise. There's also a lot of attention being placed on new acquisition Michael Morse, former top prospects Justin Smoak, Dustin Ackley, and Jesus Montero, and on a budding star at third base in Kyle Seager. So while the team's best players are getting a lot of focus and can't really be X-Factors in 2013, that doesn't mean that the team doesn't lack a player that can fill that mold.
My pick for the Mariners X-Factor in 2013 is starting pitcher Erasmo Ramirez.
Who *is* Erasmo Ramirez? He burst onto the scene in 2012, making eight starts in the majors to go along with eight relief appearances. In those 16 outings, totalling 59 innings, Ramirez struck out 48, walked just 12, and posted a 3.36 ERA. He was fantastic as a starter, the role he took on once returning to the majors in June. In those eight starts, Ramirez threw 47 innings, pitched to a 3.64 ERA, struck out 41, walked just eight, and allowed only a .609 OPS.
Ramirez, who will turn 23 in May, wasn't exactly facing cupcake teams in those eight starts either. Despite the nature of September performance being very shaky due to callups, Ramirez faced the Blue Jays, Orioles, Angels, and A's in his four September starts: two playoff teams, and two teams with excellent offenses. You also can't write his performance off completely due to Safeco Field either, because three of those four starts came away from Seattle (though Oakland and Los Angeles are pretty good pitchers parks in their own right).
Aside from his final start against the A's, Ramirez never had an outing where he walked more than two hitters. In fact, he had just one two walk outing aside from his final start of the year, a relief appearance in April against the White Sox.
Perhaps the best part about Ramirez in 2013 is that he's not really being counted on to be a bedrock in the Mariners rotation. With Hernandez, Joe Saunders, and Hisashi Iwakuma all slotted in front of him, Ramirez is just a back-end guy on Seattle this year, and he doesn't need to carry too much of the load. However, if he's able to put together a full season performance comparable to his brief 2012 performance, the Mariners could be in really good shape in 2013 with their rotation.