PITTSBURGH -- The Pirates' search for relief help has led general manager Neal Huntington to explore dozens of pitchers available on the free-agent market. So far, the club has signed lefty reliever Javier Lopez to a one-year contract and invited a few other pitchers to Spring Training under Minor League deals. But plenty of holes still remain.

Huntington's search for additional external options will certainly continue during the next few months, and plenty more signings are both expected and needed. But the Bucs may be forced to rely heavily on pitchers already within the organization, so who might those internal options be?

Who's already penciled in? Who could be a longshot to earn a spot? And who might emerge as a surprise pick, much like Jesse Chavez was last spring?

Let's take a look at some of the relievers the Pirates have or have recently had on the club's 40-man roster and what their standing looks like as Spring Training creeps closer:

Joel Hanrahan: There's no such thing as a lock for this bullpen, but Hanrahan would be pretty close to one. His 4.78 season ERA in 2009 completely masks the success he had in Pittsburgh, where Hanrahan posted a 1.72 ERA in 33 relief appearances. He's one of the top candidates to step into the closer's role and will likely get the first shot at seizing it.

Evan Meek: Much like Hanrahan, it's safe to pencil Meek into next year's 'pen already. Meek made strides with his control last season, and his success in '09 left Meek feeling he belonged in the big leagues, something he doubted after his debut in 2008. In fact, Meek might need to be ready to step into a late-inning setup role this season, particularly if Hanrahan becomes the closer.

Lopez: The left-hander is the only reliever the Pirates have signed to a Major League contract so far this offseason, which certainly puts him a step ahead as he competes to earn a spot in the bullpen. Though Lopez is the only lefty reliever on the 40-man roster, the Pirates would like him to be more than a lefty specialist. If he can find similar success to what he had with the Red Sox from 2006-08, Pittsburgh will have itself a reliable late-inning option.

Jeff Karstens: Last spring, Karstens was fighting for a rotation spot. Next spring, he'll be competing for a spot on the team, period. He was taken off the 40-man roster in November, though he's been invited to Spring Training with the chance to make the team. Karstens filled the long-relief role fairly well last season, but he will have some competition for that spot in 2010.

Chris Jakubauskas: Speaking of Karstens having more competitors, Jakubauskas represents one of them. The righty replaced Karstens on the roster last month and was an intriguing option because he has options left, while Karstens does not. Claimed off waivers from Seattle, Jakubauskas would be another long-relief candidate with spot-starting potential. Surprisingly, Jakubauskas fared better last year on the road than at pitcher-friendly Safeco Field.

Steven Jackson: Jackson ended up making 40 appearances for the Pirates last season and pitched quite well. As a result, you have to like his chances at making a strong case for a bullpen spot next year. With the Pirates lacking in left-handers, Jackson's success against left-handed hitters is certainly a plus. He held them to a .216 batting average last year.

Kevin Hart: Surprised to see Hart's name here? Well, the Pirates have recently thrown the starter's name into the list of possibilities should he not win a rotation spot. Hart does have an option left, meaning that the club might prefer to use him as a starter in Triple-A if he doesn't make the big league rotation. But if the team becomes desperate for a reliable arm, he's always an option.

Daniel McCutchen: McCutchen's situation is identical to Hart's. In fact, it's expected that the battle for the rotation's final spot will come down to the two right-handers this spring. It would be hard to see the organization take McCutchen out of a starting role so early in his career, but it's an outside possibility.

Donald Veal: Truthfully, the Bucs aren't expected to seriously entertain Veal as an option. The club is too intrigued about his potential as a starter and would much rather develop him as such in the Minors. Veal already missed out on accruing many innings last year, and the Pirates really don't want that to be the case again, even if the team is desperate for lefty help.

Justin Thomas: Pittsburgh added Thomas to the roster in October, only to take him off just weeks later. However, he's been invited to Spring Training and still has a shot at making the Major League bullpen. Thomas is a left-hander, which might help his chances, but he's going to have to show that he can be more effective against right-handed hitters than he was in 2009, when they hit .305 off him.

Ramon Aguero: Aguero is an intriguing young arm in the system, and the organization recently went so far as to protect the right-hander on the 40-man roster. He is a strike-thrower with a nasty sinking fastball, and Aguero has followed a bounce-back year with a strong showing in winter ball. However, he's only pitched in eight games above the Class A level, so Aguero might need more seasoning in the Minors before he is ready.

Anthony Claggett: Claggett was claimed off waivers in September after having had Minor League success in each of the past two seasons. But it remains to be seen if he has enough of a repertoire to be effective out of a big league bullpen. Claggett is probably a longshot to be one of the seven to break camp with the team, but management has labeled him as at least having a chance.