Complex sentence: Wallace started the 2012 season with the RedHawks, amd was recalled by Houston on June 3 when Carlos Lee was placed on the disabled list, and returned to Oklahoma City on June 17 when Lee was re-activated.
Split into simpler sentences: Wallace started the 2012 season with the RedHawks, and was recalled by Houston on June 3 when Carlos Lee was placed on the disabled list. He returned to Oklahoma City on June 17 when Lee was re-activated.