On 30 August 2010, he signed a one season loan contract with SpVgg Greuther Fürth. Kampl made his first team debut on 29 October 2010 as a late substitute in a 2. Bundesliga tie with Erzgebirge Aue. After only half a season for Greuther Fürth, he returned to Bayer Leverkusen during the 2010–11 winter transfer window. Kampl made his Leverkusen 2010–11 season debut as a second-half substitute in the UEFA Europa League game against Metalist Kharkiv. In the summer of 2011, Kampl transferred to VfL Osnabrück. After a great season at VfL Osnabrück he joined newly promoted VfR Aalen for the 250.000 euros, but only played for 3 games in which he scored and assisted 2 after which Red Bull Salzburg bought him before the end of the transfer window for 3.5 million euros. He was nominated for the best player of the Austrian Bundesliga at the beginning of the 2013–14 season, but he lost to Philipp Hosiner.