In January 1943, Hirsch enlisted in the United States Marine Corps and was transferred to the University of Michigan as part of the V-12 Navy College Training Program. In early September 1943, he broke the record at Michigan's Marine Corps training center, completing a 344-yard obstacle course in one minute and 31 seconds. He was the starting left halfback in the first seven games of the season for Fritz Crisler's 1943 Michigan Wolverines football team that compiled an 8–1 record and was ranked No. 3 in the final AP Poll. After watching Hirsch in pre-season practice, Associated Press football writer Jerry Liska referred to "squirming Elroy Hirsch" as "Wisconsin's gold-plated wartime gift to Michigan." Hirsch and Bill Daley (a V-12 transfer from Minnesota) became Michigan's most powerful offensive weapons during the 1943 season and were dubbed Michigan's "lend-lease backs."