Rich Harden — whom the Sox almost traded for at last season’s deadline — hasn’t thrown over 150 big league innings in a season since 2004.  He hasn’t posted a sub-four ERA since 2008 and he’s a fly-ball pitcher who’s home run rate has risen each of the past three seasons. Still, I believe he could be a perfect fit for the Red Sox.

Before we go any further, let’s just get one thing out of the way: Rich Harden is no longer a viable starting pitcher. Injuries are one thing, but even when healthy he has shown an inability to go deep into games. Harden made 15 starts last season, never pitching into the eighth inning and pitching seven innings only three times. In ten of his 15 starts, Harden managed to get into the sixth inning, but his ERA in the sixth inning last season was 12.96 with a .351 BA against and a .286 BABIP against, including seven home runs allowed, his most combined in any inning of 2011.

The great news is that, as a free agent, he is considering switching to a relief role, though he prefers a starting gig. It’s in this role and as spot starter, that I believe Harden could thrive for any team. There is no question that Harden has swing-and-miss stuff; his 9.9 K/9 from last season and his career 9.2 K/9 are proof of that. However, it’s the fact that his slider/cutter, splitter and changeup combination generates so many whiffs that is the key to a favorable bullpen role. Harden has typically thrown his fastball about 63 percent of the time  over his career, yet each of his three offspeed offerings generate whiff rates of over 15 percent — his slider/cutter generated an 18 percent whiff rate in 2011 compared to 20 percent from his splitter and 27 percent from his changeup. As a starter, Harden would be hard pressed to throw his slider/cutter and splitter more often, especially given his history of arm problems. However, in a bullpen role or even a swing role, he wouldn’t be counted on for much more than 60-80, maybe 100 innings, thus allowing him to mix up his pitches a bit more often. Out of the pen, he most likely wouldn’t face a batter more than once per game and could use his nasty offspeed stuff more often to his advantage, keeping hitters guessing more than ever.

As with any transition like the one I am proposing, it does not come free of risk, especially when we’re talking about an oft-injured fly-ball pitcher. Would it actually help Harden’s arm to pitch in short spurts a few days a week as opposed to 85-plus pitches every fifth day? I honestly don’t know. Then there’s the aforementioned issue of Harden being a fly-ball pitcher heading into a homer friendly ballpark. However, in a bullpen role, Harden should see a spike in his strikeout rate. Using his fastball a bit less should aide this as well as potentially aide the regression of his high home run rates. I made a point earlier about how Harden allowed seven home runs in the sixth inning last season. That seems like a clear indication that his stuff more often than not suffered late (well, late for his standards) into ballgames. Those seven sixth-inning home runs came in only 8.1 combined innings last season. On the other end of the spectrum, Harden only allowed one home run in 15 combined first inning innings last season. Harden did post a 9.00 ERA in the first inning last season, but that came alongside an extremely high .422 BABIP and is not indicative of his career numbers in the first inning. Over 160 first inning innings in his career, Harden has only allowed 12 home runs, or a 0.66 HR/9. Again, alluding to his struggles late in games, Harden’s career ERA in the sixth inning is 5.85 and he has allowed 21 home runs in a combined 97 innings or 1.9 HR/9.

Before last season, Rich Harden signed a $1.5M contract with the Oakland A’s that included performance incentives. Given his performance last season (82.2 IP, 5.12 ERA) one would have to believe that he’s not going to be seeking much more than a similar deal this offseason. Another oft-injured starter, and now former Red Sock, Erik Bedard, signed for one year and $4.5M with bonus incentives. Unlike Harden, however, Bedard has performed much better — at least in the wildly overrated, yet somehow mainstream performance indicative stat, ERA — than Harden over the past few seasons.

If any team, or in this case the Red Sox, could get Harden to consider a bullpen/spot starter role, they might be in for a bargain of a deal by seasons end. They wouldn’t be asking, or paying, for 100-plus innings, but rather bullpen depth and an emergency starter who might be worth one or two wins above replacement when all is said and done.