Born in Finspång, Steiner joined the town’s football club as an 8 year old. A few years later he moved on to local rivals Simonstorp, where he stayed throughout his teenage years. As a 19 year old he moved to Norrköping and signed for IF Sylvia, a move which proved to be very successful. He was a regular starter in the team that won the Division 3 title and who also topped the 2nd division the much following season before just being piped to the title by Assyriska. IF Sylvia failed to win a double promotion and lost the play-off against Visby.
In 1995 he signed for IFK Norrköping and he was the star of their 1997 campaign scoring 12 goals. This made him joint third top-scorer in the Allsvenskan, remarkable as IFK Norrköping only managed a mid-table placing. Steiner began to attract attention and he was included in the Sweden squad that toured Thailand, during which he earned 4 caps and scored 1 goal.
He joined Bradford on a loan later that year, and in June 1997 the move became permanent with Bradford manager Chris Kamara paying £500,000 for his services. The move at first was a success, he scored 5 goals in 8 matches and there where speculation about offers from Southampton and Lecce. Bradford were occupying top spot but injuries halted their progress and they slipped down the table. Chris Kamara was replaced by Paul Jewell and the new manger made it clear that Steiner was not in his plans. He found himself loaned out to Queens Park Rangers which was followed by a loan spell with Walsall.
He made his debut in a 2-0 away victory at Blackpool in March partnering Andy Rammell up front. His home debut was far more memorable on a personal level, with him scoring the only goal against Wrexham. Steiner helped Walsall close out promotion and chipped in with a couple of goals.
He returned to Bradford in the summer but wasn’t felt welcome and he was relieved to be given the chance to re-join QPR in a £215,000 deal. His manager Gerry Francis, unlike Paul Jewell showed total faith in him. In the 1999/2000 season Steiner scored 6 goals in 24 games, half the total of his strike partner Chris Kiwomya and QPR finished 10th in a season which is widely regarded as a great success. The following season Steiner suffered knee swelling, he was forced to play on because of a long injury list at the club. Originally when he first had surgery he was only expected to be out for 2-3 weeks. Unfortunately with the demand to fit quickly his injury returned and never fully healed. QPR were forced to release him.
Since hanging up his boots Steiner has re-joined IF Sylvia and is now the coach of their youth team where he has been for a number of years.