Ezra Shaw/Getty Images

Nate Schierholtz is a very difficult player to evaluate.

On the one hand, he's 28 years old and has a career batting line of just .270/.316/.409 in over 1,200 trips to the plate. On the other hand, he's never been given an opportunity to get regular playing time—having never received more than 360 plate appearances in a single season.

Then again, he hasn't done anything to earn more playing time, losing the starting right field job in 2010 to John Bowker in spring training, then losing the job again this year to journeyman Gregor Blanco during the first month of the season.

He has solid range and an excellent throwing arm in right field. However, he can't play centerfield, and the bat obviously hasn't been good enough to warrant a starting spot in an outfield corner. He has good speed, but isn't a great asset on the bases.

Schierholtz is now two years away from free agency. He will be arbitration eligible for the next two seasons, and he is starting to get expensive for a fourth outfielder. With a Schierholtz clone knocking on the door in Fresno for a fraction of the price in Roger Kieschnick, the time has come to ascertain Schierholtz's trade value.

Given his advancing age and cost, trading Schierholtz to a rebuilding team doesn't make a lot of sense. For a team like the Oakland Athletics or Minnesota Twins, acquiring an arbitration eligible player approaching 30 makes little sense, even if Schierholtz is better than the talent they have on hand. Instead, the best approach is to trade Schierholtz to a contending team in need of outfield depth in return for a bullpen upgrade.

Video Play Button Videos you might like

The Giants are relying on three healthy relievers right now in Clay Hensley, Javier Lopez and Jeremy Affeldt. Sergio Romo is pitching through a knee injury and Santiago Casilla has been unavailable for a week with his own knee injury. Manager Bruce Bochy clearly does not have faith in his other two relievers, Steve Edlefsen and Shane Loux.

Jared Wickerham/Getty Images

When Brian Wilson went on the shelf, Casilla moved from the seventh inning to the ninth, and Hensley took Casilla's spot in the seventh. While Hensley has been good, his fastball rarely tops 86 miles per hour, so the Giants should look to acquire a reliever who can blow a fastball by hitters in the late innings.

I outlined ten possible internal and external options to jumpstart the bullpen a few weeks ago. One trade that would make a lot of sense right now would be for the Giants to flip Schierholtz to the Pirates for Jason Grilli. The Pirates have a surplus of pitching, but their offense is dead last in all of baseball in runs scored.

Acquiring Grilli would give the Giants another late inning option who can miss bats, while Schierholtz could finally get a chance to play everyday on a Pittsburgh team that is starved for offense. The Pirates have enough relief pitching on hand to withstand the loss of Grilli, while the Giants could call up Kieschnick to replace Schierholtz.

At this point in this career, Schierholtz looks destined to be a fourth outfielder in perpetuity, until a cheaper, younger option supplants him. It is time for the Giants give him a real shot at an everyday job. Unfortunately, with the emergence of Blanco, that opportunity will have to come with a new organization.

The talent has always been there for Schierholtz, but he has never hit enough in limited playing time to get an extended opportunity. An organization with more patience might get a gem if they acquire Schierholtz.