After making four substitute appearances at the beginning of the 2004–05 season, McCormack was made available for transfer in September 2004. He joined League Two club Southend United on loan on 16 March 2005 and made his debut three days later, starting in a 3–0 victory over Cheltenham Town. In April, the loan was extended until the end of the 2004–05 season. He was an 81st-minute substitute for Mark Gower during the 2005 Football League Trophy Final against Wrexham at the Millennium Stadium, but was denied the first silverware of his career when Wrexham won the match 2–0 after extra time. McCormack scored the first senior goals of his career with a brace in a 2–1 away victory over Macclesfield Town on 19 April. He made eight appearances and scored two goals during his loan spell. He spent the entire 2005–06 season on loan at Motherwell of the Scottish Premier League, making 28 appearances in all competitions, scoring two goals, accumulating 12 yellow cards and one red.