Duensing Adding Value in Twins Rotation

It took until August for the Minnesota Twins to finally remove the struggling Nick Blackburn from the rotation. Blackburn posted an FIP above 6 in all of the first four months except for May and simply wasn’t able to keep the ball in the yard nor limit walks. As a contact pitcher – career swinging strike rate of 5.4% and a K/9 of 4.25 – Blackburn simply doesn’t have that kind of margin for error.

Blackburn’s failures in the rotation opened the door for Brian Duensing, who had been toiling as a reliever for 39 appearances over the season’s first four months. Duensing was moderately successful in that role, posting a FIP near 3.50 and compiling three runs above replacement in 45 innings. His first start came on July 23rd; since then Duensing had compiled 54 innings of 3.75 FIP baseball prior to last night’s start against the Kansas City Royals. Duensing threw eight innings in that game, allowing one run on six hits while striking out seven and walking none, which will surely increase his 1.0 WAR already accrued in the starter’s role.

Duensing probably won’t keep this kind of performance up. His 2.0 BB/9 and 0.6 HR/9 are both due for regression according to ZiPS and are both below his 2009 totals. Duensing’s skills are somewhat similar to Blackburn’s in the sense that Duensing isn’t much of a strikeout pitcher (5.0 K/9) but he misses more bats (8.1% swinging strikes) and induces slightly more grounders (52% this year, 49% career) while walking more (2.6 BB/9 career against Blackburn’s 1.9). As such, ZiPS projects a 4.37 FIP going forward. That would be below the league average FIP, but certainly decent for a starting pitcher, particularly one who wasn’t regarded as good enough to crack the starting rotation at the beginning of the season.

What Duensing represents for the Twins is the great pitching depth with which they entered the season. Duensing was the one of six pitchers projected to be worth at least 14 runs above replacement. Even without Blackburn performing up to his prior levels – a projected 2+ WAR pitcher sitting at replacement level – the Twins have been able to plug in another starter without missing a beat. Duensing’s 1.0 WAR in 54 IP prior to his last start would be great for a team’s second or third starter, much less it’s sixth. Depth like that is one reason that the Twins were projected to reach the postseason out of the AL Central this year, and, with performance like Duensing’s, it’s now a reason why they hold a 5.5 game lead as we head down the stretch.