Viking FK Born in
Tromsø, Nilsen's career began in
Tromsø, but it was after he moved on to
Viking that he became established, winning Tippeligaen, the
Norwegian top division in
1991. In his four seasons at Viking, Nilsen successfully became a regular in Norway's U21 team, and won his first senior cap in 1990. He was loaned to
1. FC Köln, and was put up for sale towards the end of the 1993 season.
Sheffield United Having already signed Norwegian team-mate
Jostein Flo,
Sheffield United boss
Dave Bassett added Nilsen in November 1993 for the fee of £500,000, beating Aberdeen to his signature. Nilsen joined as the club fought unsuccessfully against relegation from the Premier League, and was a regular at left-back. A popular figure at Bramall Lane, Nilsen played six seasons under five different managers, with a number of games at centre-back - particularly after United switched to a wing-back formation in 1997/98. He started the 1997 playoff final defeat at Wembley against Crystal Palace, and United's defeat to Newcastle in the FA Cup semi-final in 1998. It was in that cup-run where Nilsen had arguably his most memorable moment, during the quarter-final penalty shootout win over Coventry City. Never scoring for the Blades, and with Gareth Taylor having missed the first United penalty, Nilsen stepped up to convert the second - powering the ball past Steve Ogrizovic to put the Blades 1–0 up. Nilsen's final appearance came as he helped keep a clean sheet in a 3–0 win over West Brom in Feb 1999, before a surprise return to the Premier League saw him transferred to Tottenham Hotspur on a free.
Later career After making just two appearances at Spurs, Nilsen had a brief spell at
Grazer AK before he returned home to play for
Molde and
Bryne. ==International career==