Career
He has represented various Danish youth national football teams, most recently the Danish under-21 national team, playing a combined 58 youth national team matches and scoring 20 goals. As a youngster, he played for BK Frem and Rosenhøj IF where he played alongside later Brøndby teammembers Daniel Agger and Henrik Kildentoft as well as Michael Krohn-Dehli. He moved to the youth team of and Lorentzen got his first team debut for Brøndby in November 2003.
He was moved to the senior squad of Brøndby in 2004.
Foreign the 2005-2006 season, he was touted to get his breakthrough by the media, who viewed him as a coming star player for Brøndby. Due to injuries, Lorentzen only played 19 games and scored six goals in the 2005-2006 season, and he also missed out on the 2006 European Under-21 Championship in May 2006.
He again suffered injuries in the opening of the 2006-2007 season. In his comeback game in the spring of the 2006-2007 season he once again suffered an injury and is expected to be out for the rest of the season.
On 19 May 2009, Lorentzen announced that he would be leaving due to a lack of first team opportunities.
During the transfer window of summer 2009, Lorentzen joined Randers Football Club on a free transfer. He scored on in both legs of Randers Football Club"s Union of European Football Associations European League qualification round against the Irish team of Linfield. Kasper Lorentzen is left-footed and has a superb technique and is generally considered to be the player in the Danish League with the best ball control and one of the greatest talents overall, but a lack of speed and explosivity in his game and a recent suffering of several semi-serious injuries kept him outside of the starting eleven at Brøndby.
He can play both the left and right wing positions, but considers the attacking centre midfield his favourite position.
On 3 February 2015, Lorentzen announced that he would retire from professional football due to injuries, which had annoyed him throughout his career. In November 2005, he scored the winning goal for the Danish under-21 national team against the Russia under-21 team in Russia.
He has represented various Danish youth national football teams, most recently the Danish under-21 national team, playing a combined 58 youth national team matches and scoring 20 goals. International goals Club Individual.