“Man of Steel” thesp Christopher Meloni is in negotiations to join Harrison Ford and Chadwick Boseman in Legendary Pictures’ baseball drama “42.”Boseman stars as Jackie Robinson, while Ford will play Branch Rickey. Meloni will play Leo Durocher, the manager of the Brooklyn Dodgers. Brian Helegeland is writing and directing the pic, which will be produced by Legendary’s chairman/CEO Thomas Tull, and exec produced by Legendary prexy/CCO Jon Jashni. Former Disney chairman Dick Cook will also exec produce. Meloni is best known for playing Det. Elliot Stabler on “Law & Order: Special Victims Unit” for more than a decade. Thesp, who recently co-direct National Lampoon’s sketch comedy pic “Dirty Movie,” will soon be seen on HBO’s “True Blood.” Meloni is repped by Gersh and Industry Entertainment.