It’s been a long time since Kerry Wood struck out twenty as a Chicago Cub.

A long time, filled with injuries and disappointments and ultimately relegation to bullpen duty. Many point to Wood’s struggles, and that of another one-time Chicago Cub, Mark Prior, in being the impetus towards today’s obsession with young pitchers and doing everything possible shy of actual bubble wrap to protect them (see “Strasburg, Stephen” and “Joba Rules” (the latter under 2007/2008 entries) ).

It’s been a long time and I’m not sure how many ever thought he’d find himself playing for the Yankees–certainly not as a late inning reliever, and one fourth on the pecking order, after Mariano, Robertson and Joba–and yet, here his is, quickly becoming Cashman’s best mid-season acquisition of the year.

Just think about where the Yankees’ bullpen was before the deadline: outside of Mariano, and possibly Robertson, there was perhaps no one in whom Yankee fans had much faith. Joba may not have been blowing leads left and right, but it felt like it, and Logan pitched so poorly he was optioned to the minors.

Enter Wood, who as a Yankee has an ERA under one and thirteen strikeouts in 10.2 innings pitched (before Tuesday’s game). In fact, the only run Wood has allowed as a Yankee, inherited or otherwise, came on a solo home run–that on August 3rd, Wood’s second ever game in pinstripes.

He’s not allowed a run since.

In fact, if one looks at Wood’s gamelogs, one will see that 1/3rd of all runs Wood has given up this year came in one third of one inning against Kansas City on May 19th*

That’s not to say he hasn’t allowed baserunners–seven walks and nine hits as a Yankee (as of Tuesday afternoon) say otherwise–but no runs is still no runs.

When Sergio Mitre and Chad Gaudin seem to be battling to find out who wants to get DFA’d first and the starting rotation is such that only 2/5ths of it are healthy and pitching as they’re supposed to be pitching, Wood’s performance is a breath of fresh air.

*Thanks to blog reader JGS (http://twitter.com/jordan_smed)