Whilst playing for Chorley, in July 2015 he became the first team Manager succeeding Flitcroft. In his first season, he guided the team to an 8th placed finish in the National League North, and reached the play-off final in 2016-17 suffering a marginal defeat. Jansen has played for various clubs including Carlisle United, Crystal Palace, Blackburn Rovers and Bolton Wanderers. He was a striker and scored 44 goals in 153 appearances for Blackburn.