Tom Wilhelmsen emerged in the second half of 2012 as the Mariners' closer. The question for 2013 fantasy owners is whether he can keep the job in 2013, given the inherent volatility of the position.
Coming into the 2012 season, Tom Wilhelmsen and I had exactly the same number of saves at the major league level. By the end of the season, he stood 29 saves ahead of me, and should pull further ahead in 2013. The 29 year old right-hander's fastball sits in the mid-90's and there is enough separation between that and his 78 mph curveball to help make him effective. Along with the aforementioned 29 saves, Tom fanned 87 in 79 innings, and posted a very respectable 2.50 ERA and 1.11 WHIP. Those numbers should make Mr. Wilhelmsen a fantasy-favorite in 2013. The difficulty, however, is that 2012 was his first year in the role, and the inherent turnover of closers means that, in a world where nothing is guaranteed, this is even less-so, if you are a ninth inning specialist.
As it stands, I look for Tom to get 31 saves, and continue to be an effective fantasy pitcher. His 2012 K/9 of 9.91 may be difficult to sustain, but given his minor league history, there is no reason he cannot maintain a ratio close to 8.5 K/9. His walk rate has always been at or over 3 walks/9 IP, so I do not think you will see an improvement there. Given those last two metrics, I would be more comfortable predicting an ERA of 3.72, than a repeat of the 2.50 from 2012, and I think the WHIP will inch upwards, slightly, to 1.26. This should be enough for Tom to keep his job in 2013, but since he does not have the longevity of Kimbrel or Papelbon, you may want to keep a bench slot available for Stephen Pryor or Carter Capps (in that order), just in case he falters. Even if that happens, though, I believe Tom will eventually regain the role, after making whatever adjustments are necessary, so hang onto him when the inevitable occurs. As with Brandon League in 2012, we know it only takes a few blown saves, in Seattle, to lose a job.