Pollock was succeeded by Lieutenant Colonel William W. Stickney on 23 September 1942 and was subsequently appointed Executive Officer of the 1st Marines. He was later transferred to the staff of the 1st Marine Division under Major General William H. Rupertus and appointed Assistant Chief of Staff (G-3) for plans and operations in July 1943. Pollock was promoted to the rank of colonel in November 1943 and then served in this capacity during the Battle of Cape Gloucester in December 1943. He later earned the Legion of Merit with Combat "V" for his part in the battle.