MLB teams are working to keep their best pitchers off of the open market with contract extensions, and fewer elite arms are hitting free agency as a result of this emerging trend. In the past month alone, Matt Cain, Derek Holland, Jon Niese and Madison Bumgarner have signed long-term extensions that will postpone their free agency.

So who's going to hit free agency? Fortunately for teams without pitching, some under-30 starters are not signed to long-term deals (minimum 2.5 wins above replacement in 2011 per FanGraphs). The list below includes pitchers who are going year to year through arbitration, and those who are headed for free agency this coming offseason:

Eligible For Free Agency After 2012

• Zack Greinke -- 28 years old, 3.9 WAR in '11, 7.057 years of MLB service through '11
• Edwin Jackson -- 28 years old, 3.8 WAR in '11, 6.070 years of MLB service through '11
• Cole Hamels -- 28 years old, 5.0 WAR in '11, 5.143 years of MLB service through '11 (extension candidate)
• Brandon McCarthy -- 28 years old, 4.7 WAR in '11, 5.122 years of MLB service through '11 (extension candidate)
• Anibal Sanchez -- 28 years old, 3.8 WAR in '11, 5.099 years of MLB service through '11 (extension candidate)

Eligible For Free Agency After 2013

• Matt Garza -- 28 years old, 5.0 WAR in '11, 4.149 years of MLB service through '11 (extension candidate)

Eligible For Free Agency After 2014

• Justin Masterson -- 27 years old, 4.9 WAR in '11, 3.108 years of MLB service through '11 (extension candidate)
• Matt Harrison -- 26 years old, 4.2 WAR in '11, 3.083 years of MLB service through '11
• Max Scherzer -- 27 years old, 2.8 WAR in '11, 3.079 years of MLB service through '11 (extension candidate)

Eligible For Free Agency After 2015

• Rick Porcello -- 23 years old, 2.7 WAR in '11, 2.170 years of MLB service through '11
• David Price -- 26 years old, 4.7 WAR in '11, 2.164 years of MLB service through '11
• Jordan Zimmermann -- 25 years old, 3.4 WAR in '11, 2.154 years of MLB service through '11 (extension candidate)
• Ian Kennedy -- 27 years old, 5.0 WAR in '11, 2.124 years of MLB service through '11 (extension candidate)
• Mat Latos -- 24 years old, 3.2 WAR in '11, 2.079 years of MLB service through '11
• Doug Fister -- 28 years old, 5.5 WAR in '11, 2.058 years of MLB service through '11
• Philip Humber -- 29 years old, 3.5 WAR in '11, 2.000 years of MLB service through '11

Eligible For Free Agency After 2016

• Daniel Hudson -- 25 years old, 4.9 WAR in '11, 1.117 years of MLB service through '11 (extension candidate)
• Ivan Nova -- 25 years old, 2.7 WAR in '11, 1.035 years of MLB service through '11
• Brandon Beachy -- 25 years old, 2.8 WAR in '11, 1.014 years of MLB service through '11
• Michael Pineda -- 23 years old, 3.4 WAR in '11, 1.000 years of MLB service through '11

Many of the pitchers above will eventually sign extensions that delay their arrival on the open market. For now, however, it remains possible that they'll test free agency.