As the hot stove heats up, we turn our sights to free agent outfielder Jayson Werth, who could add a spark to both the 2011 lineup and rumor mill should he sign with Boston…

Of the top position players available on this year’s free agent market, Phillies outfielder Jayson Werth is arguably the second best hitter, combining a patient approach with the requisite power to man a corner outfield slot for a playoff-caliber team.

Werth makes decent contact, though he is held back by a relative inability to make adequate contact with pitches in the zone. Of any one plate discipline indicator, zone contact percentage has the most affect on strikeout rates and Werth’s zone contact rate of 82.2 ranked 11th worst of 149 qualified batters in 2010 — right behind teammate and strikeout extraordinaire Ryan Howard (10th; 82.0).

This tendency will keep his strikeout rate right around 25 percent, which tends to be the line where strikeouts turn from annoying to detrimental. A rate in the high 20s is damaging to most all, while a rate in the 30s is universally unrecoverable except for elite-level power and line drive hitters. At this point, strikeout rates begin to overwhelm a hitter’s batting average, taking OBP and OPS down with it.

Luckily, Werth lies just below these landmarks, even if he is unlikely to approach .300 again like he did in 2010. Still, a batting average of around .270-.280 is more than adequate, while his .370 OBP and high .800s OPS will bring home the bacon.

While his low zone contact percentage is something to keep an eye on, it won’t prevent Werth from being a star for the Red Sox.

Of more concern is his age in what will likely be a four or five year deal — and therefore the threat of decline in the latter years of his contract. Turning 32 in May of next season, Werth is all but guaranteed to be signed through his age-35 season, with a very real chance of being 36 should he sign a five-year deal.

While Werth’s decline should be slowed by his excellent athleticism, perhaps one area of concern is his height — and therefore the length of his arms. As ESPN’s Keith Law pointed out in his most recent article, Werth is unique in that he likes pitches on the inside half despite being a lanky 6-foot-5. For a hitter that earns his paycheck on the inner part of the plate, Werth is a candidate for accelerated decline as his bat speed slows.

Since his long arms necessitate excellent bat speed to catch up to inside fastballs, any loss of said bat speed could accelerate his decline. There’s a reason why 5-foot-9 Matt Stairs hit six home runs at age 42, while 6-foot-8 Richie Sexson hasn’t hit one since he was 33. Long arms take longer to get through the hitting zone and are therefore more vulnerable to good fastballs.

In Werth’s defense, however, he has shown the ability to hit to the opposite field, which will aid him later in his career. Tall, all-pull hitters aren’t a good bet to age well, so it’s a good thing Werth can go to right field when he needs to.

Admittedly, we’re being a bit nitpicky — and it may be a bit unfair to spend so much time discussing the drawbacks of such a talented player. But we would be remiss not to point out the outfielder’s flaws, especially one whose prime years are coming to a close.

He really does a lot well. He fits the bill for a middle of the order Red Sox’ bat — a good hitter, with a patient approach and plenty of power. He’s a good athlete with speed who can ably man a corner outfield position.

He’s selective at the plate, swinging at around 40 percent of pitches he sees, while being somewhat aggressive — as evidenced by his 21.8 percent O-Swing rate.

At the end of the day, he’s a tremendous hitter who would be a welcome asset to the Red Sox lineup.

Ideally, the Sox would be able to add Werth via a four-year deal — getting two or three excellent years while hoping for the best in the final season of his contract.

Expect the Sox to go hard after Werth, but all the while leaving one foot out the door depending on the availability of Carl Crawford. As good as Werth is, he’s not at Crawford’s elite level, ceding about 1-2 WAR in any given year.

Still, what Werth gives up in raw value he’ll get back in flexibility, as it’s more difficult to find a right fielder than a left fielder. If the Sox find a way to sign Crawford to left field this offseason, they may find there is no adequate right field option on free agency after 2011 when J.D. Drew departs.

Left field is, historically, the easier position to fill due to easier defensive responsibilities. Any outfielder can be shifted to left, while right takes a cannon of an arm. Bottom line is, if the Sox sign Crawford, they get the better, younger player, while leaving open the chance of not having an adequate right fielder in 2012. If the Sox sign Werth, they go with a less-talented (but still very good) option, but one whom allows them to go after any outfielder next offseason. It’s a nice bit of flexibility that any Bill Belichick supporter would certainly enjoy.

Still, perhaps the most interesting component of a Jayson Werth signing — or Carl Crawford, for that matter – is how it would shape the Sox’ 2011 outfield situation, Jacoby Ellsbury’s status with the 2011 team, and thus, the organization’s entire 2010-11 off-season. The signing of either one would give the Sox four starting caliber outfielders (Werth/Crawford, Drew, Mike Cameron, and Jacoby Ellsbury) for three starting positions — a veritable logjam confounded with huge contracts.

While some would (and are currently) advocate for the trade of Ellsbury, the smart money would be to just keep Ellsbury as a fourth outfielder.

It couldn’t make more sense.

1)      While Ellsbury and Cameron would vulture one another’s playing time in center, both are terribly injury-prone and require one another as a mutual insurance policy.

2)      Drew and Cameron both enter free agency following 2011, meaning that the Sox, if they traded Ellsbury, would be left with just Werth entering 2012.

3)      Despite a lost 2010, Ellsbury remains extremely talented, albeit a work in progress. Short of receiving a huge prospect haul (which was made unlikely by his injury-plagued 2010), the club would be best served seeing if Jacoby could recapture his prospect status with a full 2011.

A fourth reason: it would give writers, Boston fans, WEEI, the Sports Hub, and every media outlet an endless supply of ammunition for their daily talk.

Further compounding the situation, what would the team do with an emergent Darnell McDonald, a cheap solution as fourth outfielder?

But I digress.

Though the club would have an expensive logjam in the outfield, and has more pressing needs at catcher and third base, don’t feel guilty in rooting hard for the acquisition of Jayson Werth. An exceptional player, he’ll be worth the $16-17 million per year that he should eventually receive.

However, as Werth will be virtually inseperable from Carl Crawford this offseason, keep your fingers crossed for Crawford, but don’t be disappointed with Werth as an excellent Plan B.