German Under-21 international midfielder snapped up from Hertha Berlin in July, 2007.
Progressed through the ranks of the Bundesliga club and played 18 times, scoring three goals, for the reserves in the Regionalla Nord aged just 17 in 2004-05.
He was soon in the first team and capped his first season in Germany's top flight by winning the prestigious Fritz Walter Gold Medal Award as the Young Player of the Season.
Berlin-born Kevin played 42 times in the Bundesliga, scoring four goals and added to his experience with six appearances in the UEFA Cup, scoring once.
Gareth signed from Southampton