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Not Buying Jorge de la Rosa

After only pitching a total of 69.2 innings in 2011 and 2012, Jorge de la Rosa has enjoyed a productive bounce-back season in which he’s compiled a 3.31 ERA, and his 16 wins are the second-most in Major League Baseball. Those two statistics have made de la Rosa extremely relevant in standard rotisserie leagues. In fact, he’s been more valuable than Justin Verlander, Gio Gonzalez and Kris Medlen in ESPN leagues, which immediately demands attention.

That value is what makes his 44.6% ownership rate in ESPN leagues so fascinating. He’s widely available on the waiver wire in most leagues, yet he’s been effective all season — including recent starts. The southpaw hasn’t surrendered more than three earned runs in a start since July 29 and has won six-consecutive decisions. Although pitcher wins remain a roll of the dice in many ways, it’s surprising such a stretch would fly under the radar for so many owners, leaving him on the waiver wire collecting fantasy points for no one.

The fantasy baseball community has seemingly decided this level of performance is largely unsustainable, essentially treating him like fellow left-hander Jeff Locke who has similar ownership rates. Unlike Locke, though, de la Rosa hasn’t imploded down the stretch. He continues to find success and has been the 30th-ranked starting pitcher over the last 30 days.

It’s not difficult to determine why owners are so skittish with de la Rosa. Despite a good ERA and solid FIP, he’s a pitcher who doesn’t strikeout many batters and struggles with his command at times. Thus, his 1.36 WHIP is above the league-average mark, and we’re already talking about two standard categories (strikeouts and WHIP) where the left-hander is a liability for fantasy owners.

However, de la Rosa owns a career 7.60 K/9 strikeout rate. Is it reasonable for owners to expect his strikeout rate to return to career norms? Perhaps it rebounds a bit, but the underlying numbers suggest his overall stuff has declined — which should be expected to some extent, considering he’s now 32 years old and coming off Tommy John surgery. His fastball velocity averaged 93.4 mph in 2010 (the year prior to his elbow injury) and only 91.0 mph this season. His current 9.4% swinging-strike rate is well below his norm since he joined the Rockies in 2008.

Year SwStr%
2008 10.4%
2009 10.8%
2010 11.2%
2011 11.4%
2012 12.3%
2013 9.4%

Opposing hitters have always found success against de la Rosa’s fastball. Instead, his effectiveness comes from his offspeed pitches, especially his splitter (which used to be categorized as a changeup). His split-fingered fastball has traditionally generated a swinging strike 21-22% of the time. This season, though, his swinging-strike rate on his splitter has fallen to 17.9%, so it makes sense his overall swinging-strike rate and strikeout rate have both experienced a decrease.

And not only has he struggled to miss as many bats with his splitter, but he’s not experiencing as much success with the pitch in general. Check out past performance against his changeup/splitter:

2009 .177 .275 21.0%
2010 .203 .325 22.1%
2011 .136 .214 22.9%
2012 .211 .263 21.3%
2013 .242 .275 17.9%

De la Rosa gets his whiffs from his splitter and slider, though his splitter/changeup has become his go-to secondary offering since the 2010 season. It hasn’t been as good this season, so his strikeouts are down. Yet, strangely, his ERA is stellar. No wonder fantasy owners have shied away from the left-hander this season. Furthermore, his 4.40 SIERA is very concerning, and looking at his rate statistics, one would expect his home run rate to climb. Not simply because he’s primarily pitching in Coor’s Field, but also because his 7.1% HR/FB and 0.54 HR/9 rates are well below his career averages. Combine those two things together, and it seems reasonable to project some home run troubles in the future for de la Rosa.

At this point, though, there’s less than a month remaining in the season. Perhaps he can hold it together for another few weeks and continue to be a useful fantasy starter. Anything can happen in a month of baseball. However, considering the low strikeout rate, decreased effectiveness of his splitter, potential home run regression and heavy reliance on wins for value, Jorge de la Rosa is not someone I would recommend plucking off waivers for the stretch run unless you’re playing in a deeper league — though, in that case, he’s probably already claimed.