Recently, we wrote about the Cardinals’ search for a second lefty to use out of the bullpen, and how John Mozeliak seemed focused on importing such a player from outside of the organization. Obviously, this pointed to Motown working out a trade or making a free agent signing, and this was somewhat problematic for us, as there are already plenty of relievers on the roster that are good enough to get left-handed batters out, even if they are not themselves left-handed. Oh, and we also don’t like contracts like the ones handed out to Jonathan Broxton and Jeremy Affeldt; we just pity teams that do things like that, in fact.

So now the rumors are flying about a possible spark between the Cardinals and Sean Burnett, a 30-year-old southpaw coming off an excellent season in the nation’s capital, where he nearly beat out Barack Obama in the presidential race. Burnett was worth 1.1 WAR (a fine total for a reliever who threw just 56.1 innings) in 2012, and all his peripherals look mighty tasty: he whiffed just over a batter an inning (9.1), walked just under two batters per nine (1.9), and kept both his FIP (2.79) and xFIP (2.84) under the 3.00 mark. He’s also extremely adept at getting ground ball outs (57.4% in 2012), and he held opposing left-handers to a .237 wOBA a season ago. So what’s not to like? In a word, plenty.

Yes, Burnett is coming off a nice season out of the bullpen. If he could manage to repeat 2012 for the next few years, we suppose he may be worthy of a two-year deal for a team that has no reliable way to retire left-handed opponents. We even suppose that if he repeated 2012 the next few years, the Cardinals could even ink him to a modest contract and we wouldn’t riot too much. We wouldn’t be thrilled to death about it, but we absolutely would not launch into a patented profanity-laced tirade or kidnap any more members of the front office in protest, either; you have our word on that.

The thing is, it doesn’t seem all that likely that Burnett will repeat his 2012 the next two or three seasons. Just a year ago, in fact, he was coming off of a season in which he pitched the exact same amount of innings as he did in 2012, and the results were nowhere near as good. His strikeout and walk rates both went the wrong direction in nearly doubled fashion, his FIP was 4.51, and he was actually worth negative value in terms of WAR. Again, this just happened in 2011, and he had been coming off a nice season the year before that, one was that by some accounts even better than the season he just had. Say this with us, friends, and repeat it to yourself in a toneless chant, a mantra that can guide you through every problem that comes up in your life: relievers are volatile. Say it again: relievers are volatile.

In fact, Burnett’s last four seasons perfectly illustrate exactly why it is a relief pitcher shouldn’t be trusted with anything approaching a long-term contract. The whole alternating useful seasons with ones in which any minor league journeyman (read: Barret Browning) would have done a better job is very disconcerting. There are relief pitchers who don’t see this kind of swing in their stats, so don’t get us wrong, but they aren’t especially common, and Sean Burnett does not enter that territory. He’s a decidedly ho-hum relief pitcher in the end, someone who has managed two solid seasons and four utterly forgettable ones over six years in the major leagues. His career numbers back up this point admirably; go give them a look, and if you’re too lazy to, just trust us when we say they’re not at all in line with what he’s done in his two good seasons.

Burnett, for what it’s worth, is certainly a viable lefty specialist. A season ago, he held left-handers to a .237 wOBA, and that number sits at .277 over his full career — he can get them out just fine. He’s not exactly a complete disaster against righties, either, but it’s hard to imagine a situation with any kind of leverage attached at all where he wouldn’t be a manager’s last option, or at least one of them. Last year, right-handed hitters batted .293/.347/.420 against Burnett (.327 wOBA), and for his career they’re batting .262/.348/.398 (.325 wOBA). The point is, however, that the Cardinals — or any other team who acquires Burnett — is not going to be paying him good money because he turns all right-handers into slightly above-average hitters; they’re going to be looking at his ability to silence the left-handed bats.

Let’s return again to the subject of the pitchers the Cardinals already have and do a little comparison here to see how Burnett stacks up. We briefly mentioned this in the last post on the subject, but this time we thought we’d go ahead and bring the statistics over here so you can judge for yourself. See how amazingly useful we are? The Cardinals should give us the contract they’re willing to give to Burnett just so we can churn out even more posts like this one. The numbers to the  left of the slash are from 2012, while the numbers to the right are career statistics.

Burnett: .209/.245/.289, .237 wOBA (95 TBF) | .221/.291/.337, .277 wOBA (588 TBF)
Rzepczynski: .255/.320/.362, .304 wOBA (103 TBF) | .218/.299/.307, .276 wOBA (347 TBF)
Motte: .122/.194/.187, .175 wOBA (134 TBF) | .229/.311/.359, .295 wOBA (419 TBF)
Boggs: .236/.322/.333, .289 wOBA (123 TBF) | .288/.383/.473, .371 wOBA (525 TBF)
Mujica: .244/.269/.400, .282 wOBA (119 TBF) | .255/.294/.423, .305 wOBA (702 TBF)
Salas: .264/.343/.337, .290 wOBA (101 TBF) | .237/.316/.386,  .302 wOBA (285 TBF)
Rosenthal: 143/.167/.229, .175 wOBA (36 TBF) | .143/.167/.229, .175 wOBA (36 TBF)

You can see that when it comes to career numbers, Burnett would immediately be the second best option on the team when it comes to retiring the other team’s left-handed hitters. You can also see how bad Marc Rzepcynski was last season compared to how solid he normally is, and even if there’s no way he has a chance at making it as a starter, he’s a good bet to rebound against his own kind in 2012; his career numbers show that he’s an even better option against them than Burnett is.

As for the other names? Obviously, Jason Motte can’t be used at any arbitrary point in a game just because a dangerous left-hander is up, but surely Matheny can recognize how nasty he is and perhaps bring him in a little earlier than he normally might if a string of them are coming up near the end of a game. Mitchell Boggs has come a long way from his days as a failed starter, and I’d wager that his career numbers against lefties no longer tell the real story. Edward Mujica has faced more left-handed hitters in his career than anyone on that list, so you know he’s a proven asset against them, something that should make the raise he gets through arbitration this year a little easier to stomach. We were surprised to see that Fernando Salas has such solid numbers against left-handed hitters, but the numbers are very convincing there; this helps to remind us that even if he has fallen back on the depth chart, he could still be very useful to the big league team. Then of course there’s Trevor Rosenthal, who we included on this list despite a very small sample size because, well, he’s amazing, and we couldn’t resist.

Look, Burnett is a reliable left-handed specialist. He’d immediately be among the team’s top choices in a late game situation facing a tough lefty bat. We have to stand firm on this issue, however, because once again, the Cardinals already have multiple options they can use out of the bullpen to keep a pretty firm grasp on any late game situation. Affledt cost the Giants $18 million over three seasons, and Burnett won’t have to settle for much less than that. There’s just no way to justify that kind of salary for a guy who may or may not be a below-replacement level player over the next several coming seasons, not with so many good lefty neutralizers already in place.

Tagged: Left-Handed Relievers, Sean Burnett, St. Louis Cardinals