 He made ten Bundesliga appearances during his loan, but was forced to miss the final two matches of the season for a suspension of four matches imposed by the German Football Association (DFB) following a tough challenge and "no-nonsense flying kick" to the head of VfL Wolfsburg's Makoto Hasebe.Dortmund were eager to sign Boateng permanently at the end of the season, but financial constraints prevented them from doing so.English Premier League club Portsmouth signed Boateng on a three-year contract in August 2009 for a reported fee of around £4 million.