This weekend, the Twins unveiled their newest bullpen weapon, Brian Fuentes, who they acquired dirt cheap from the Angels. As Aaron has pointed out, while Fuentes is no longer an elite reliever, he’s still very effective, particularly against lefties. And while neither he nor the club’s other “closer”-type, righty Matt Capps, have the ability to replace Joe Nathan’s end of game dominance, together they form a two-headed attack that might be just as effective.
From 2007-2009, Joe Nathan posted incredible numbers against both lefty and righty hitters:
Now, that’s what an elite reliever is supposed to look like. Nathan strikes out a ton of guys, doesn’t walk many, and keeps the ball in the park. During the same time frame (minus Matt Capps’ out-of-character 2009), here’s what you get from a combination of Fuentes’ work vs. LHB, and Capps’ vs. RHB:
As you can see, there’s only a very slight bump in OBP (less than a .02 difference) and SLG (less than a .03 difference). The Capps/Fuentes combination suffers slightly because they strike fewer batters out, but they’re walk rate is also significantly lower than Nathans, and gives them a distinct advantage in K/BB. They also allow slightly fewer homers per nine innings than Nathan does.
This is not to say that the Twins are better off with Fuentes/Capps than they would be with Nathan. Because Nathan combines the best of both pitchers, he does not show a platoon advantage. Also, he only takes up one roster spot. But with the September roster expansion just two days away and the Twins carrying 12 pitchers anyway, there shouldn’t be a significant concern about the Twins being short on pitching for the last month of the year. Mixing and matching at the end of games based on matchups would give the Twins a stronger back end of their bullpen while Nathan is absent.
Gardy now has a bullpen that can mirror that of the Davey Johnson-era Mets (who, not coincidentally, Gardenhire played for), who had tremendous success using Doug Sisk, Roger McDowell, Jesse Orosco, and Randy Myers at various times to close out wins. Indeed, during Nick-Blackburn’s near shutout against the Mariners, Gardenhire made the smart play to bring Fuentes in to close out the win against Russell Branyon, rather than turning to “closer” Capps. If Gardy makes a habit of playing the match-up game like this, the Twins will be almost as unbeatable in the 9th as when Joe Nathan was healthy. And with Crain, Rauch, and whichever of Fuentes/Capps does not pitch the 9th available to pitch the 8th, the Twins have the ability to shorten games even further.