He is the setup man, the proven commodity, the bridge from the 7th to Soria. Over the last two seasons, Robinson Tejeda performed about as well as you could expect him to. In 2010, he cut his BB/9 from 6.11 to 3.84 while maintaining a very high K/9 ratio (10.63 and 8.26, respectively). His ERA, FIP, and xFIP between the two seasons were stark in their similarities as well: 3.54 ERA both seasons, FIP's of 3.60 and 3.59, and xFIP's of 4.41 and 4.26. He also started six games in 2009, and pitched well. In four of his starts, he went 5.0+ innings and gave up one run or less. In another, he went five and gave up three. Only in one start did he pitch poorly, giving up six runs (five earned) in 4.1 innings.
But something alarming has happened to start this season: his velocity has decreased dramatically.
It may be a statistical anomaly, but Tejeda has posted more of the lowest average velocity trends this year than he has in his previous four seasons combined.
Fastball velocity, average and range, since 2007:
[click for full-size]
It wouldn't be alarming at all if it wasn't such a stark difference. An mph or two here and there is to be expected, but the compacted snare of his range is even more telling. He hasn't thrown a pitch faster than 91.9, whereas in the last three seasons his median average was 94.
Another interesting thing is that Tejeda's spin angle is virtually the same on his fastball as it is on his changeup:
I wonder if this makes it harder to delineate between his fastball and changeup as far as collecting Pitchf/x data is considered. But moreso, you can see that several of Tejeda's pitches classifed as changeups have less than a 5mph difference with the velocity of fastball he has been throwing so far this season.
According to FanGraphs, the average velocity of his fastball is sitting at 88.7, which is 5mph slower than last year (93.7) and 5.5mph slower than his previous two seasons before that (94.2).
Again, this is a very small sample size. His 5.1 innings is only about 8%-9% of what he threw all of last year. But it certainly is something to keep an eye on as the year progresses. But, he has never shown a propensity to start a year with sub-par velocity and then kick it up once the weather warms up.
And to this end we come full circle: In his 5.1 innings this year, Tejeda has 1 strikeout. On the flip side, he has been able to get away with it, because he only has given up one free pass as well. It also behooves me to mention that, much like Joakim Soria, Tejeda only has three swinging strikes in his appearances so far this year.
What does all this mean? Who knows. Tejeda's placement on this roster lasts only as long as he is a viable pitcher. If he regresses this season, it might not be that big of a deal, considering how well Jeffress, Crow, and Collins have pitched so far.
Nevertheless, it is something to keep a look out for. I like Tejeda as a player and he has done a more-than-adequate job holding games for Soria. Consistent, productive bullpen arms are a rare thing, and Tejeda has been that over the last couple of seasons.