With MLB's free-agency period just around the corner, the Josh Hamiltons and Zack Greinkes of the world are sparking the most buzz, but don't forget about the underrated players of the league who could prove to be huge signings down the line.

Whether you need a backstop, an outfielder or an infielder, there are several players on the market in the 2013 class that have a lot to offer and probably won't demand a huge sum of money.

Here are my most underrated position players in baseball's 2013 free-agent class.

3. Jeff Keppinger, INF

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Jeff Keppinger has been a productive player in the major leagues ever since his 2010 season with the Houston Astros.

He hit a combined .277 with six home runs, 35 RBI and 39 runs in 99 games with the Astros and San Francisco Giants last season while compiling a .987 fielding percentage at second base.

This season with the Tampa Bay Rays, the 32-year-old batted .325 with nine home runs, 40 RBI and 46 runs in 115 games while compiling a .991 fielding percentage at first base, second base and third base.

2. A.J. Pierzynski, C

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The fact that A.J. Pierzynski didn't even make the All-Star roster in 2012, even as a reserve, tells you all you need to know about how underrated he is.

He not only hit .278 with 27 home runs, 77 RBI and 68 runs at the catcher position, he posted a .994 fielding percentage while catching Philip Humber's perfect game in April.

I'm guessing it has to do with him been voted the most hated player in baseball in June, per CSNBayArea.com.

1. Angel Pagan, OF

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Angel Pagan's impact this season for the world champion San Francisco Giants goes beyond his 95 runs or his 29 stolen bases.

He was a catalyst at the leadoff position for the Giants and his leadership, combined with his fielding, made him one of San Francisco's favorite players.

Pagan was seventh in fielding percentage among qualifying National League center fielders this season, but he also made some spectacular plays and posted a perfect fielding percentage in the playoffs.

You want to know how big Pagan was for San Francisco this season?

Ask Giants fans.