▁day . ▁On ▁May ▁ 2 0 , ▁Walker ' s ▁b ob ble head ▁night ▁at ▁P NC ▁Park , ▁he ▁drove ▁in ▁a ▁career - high ▁ 5 ▁R B Is ▁against ▁the ▁Detroit ▁Tig ers ▁in ▁a ▁ 1 0 – 1 ▁Pir ate ▁win . ▁▁ 2 0 1 2 ▁After ▁dealing ▁with ▁various ▁back ▁issues ▁in ▁August ▁and ▁September , ▁Walker ▁was ▁shut ▁down ▁for ▁the ▁season ▁on ▁September ▁ 2 9 ▁with ▁a ▁h erni ated ▁disc ▁in ▁his ▁back . ▁▁ 2 0 1 3 ▁Walker ▁was ▁activ ated ▁from ▁the ▁disabled ▁list ▁on ▁May ▁ 1 3 ▁after ▁sp ending ▁some ▁time ▁with ▁the ▁Al to ona ▁Cur ve . ▁▁ 2 0 1 4 ▁Walker ▁was ▁placed ▁on ▁the ▁disabled ▁list ▁June ▁ 9 ▁after ▁under going ▁an ▁emer gency ▁App ende ct omy ▁thus ▁allowing ▁a ▁ro ster ▁spot ▁for ▁top ▁prospect ▁Gregory ▁Pol an co . ▁On ▁Open ing ▁Day ▁March ▁ 3 1 , ▁Walker ▁hit ▁a ▁walk ▁off ▁home ▁run ▁in ▁a ▁ 1 - 0 ▁victory ▁in ▁the ▁ 1 0 th ▁against ▁the ▁Chicago ▁C ubs . ▁On ▁September ▁ 1 4 , ▁Walker ▁hit ▁his ▁ 2 0 th ▁home ▁run ▁of ▁the ▁season ▁( a ▁new ▁career ▁high ) ▁also ▁setting ▁a ▁new ▁record ▁for ▁home ▁runs ▁in ▁a ▁season ▁by ▁Pir ates ▁second - bas emen , ▁a ▁record ▁which ▁was ▁previously ▁held ▁by ▁Bill ▁Maz eros ki . ▁ ▁Walker ▁ended ▁the ▁ 2