manager Jim Smith signed Harper for £300,000 in September 1998. Harper scored two goals for Derby; one against Liverpool in the league and one against Swansea City in the FA Cup. He was loaned out to Walsall in December 1999 for the remainder of the season. His spell at Walsall was cut short when Portsmouth made an offer of £300,000 for his services in March 2000. Harper moved to Fratton Park having started only seven games for Derby. The Scottish under-21 international soon settled into the team at Portsmouth, but missed much of the 2000–01 season with a shin splints problem. In 2001–02 he had the dubious honour of having been sent off more times than he scored. However, he was a crucial member of the side that won the First Division title in 2002–03, and his excellent performances down either wing for Portsmouth earned him two monthly 'Swan d'Or' awards from the Norwegian Press Club and a place in the full Scotland squad. Despite his impressive part in Portsmouth's promotion, Harper was loaned out to Norwich in September 2003. His loan spell at Carrow Road was initially for one month but was extended to three months. He played well at Norwich, but was also sent off for a two-footed tackle on Luciano Zavagno in a match against Derby County. He contributed nine league appearances during Norwich's 2003/04 season after which they were promoted to the Premier League as First Division champions in his absence. On his return to Fratton Park he made only nine appearances for Portsmouth in the 2003–04 season. After failing to regain his place at the start of the 2004–05 season he was loaned to Leicester City. In January 2005 was sold to Stoke City. Despite starting his Stoke career impressively, Harper was dogged by injuries that prevented him challenging for a first team place. He scored once for Stoke, in a 3–1 win over Norwich City. Harper was loaned to Carlisle United in October 2006 and then Walsall, whom he had played for on loan earlier in his career. He was released by Stoke manager Tony Pulis in May 2007.
Return to Scotland
On 7 July 2007, Harper opted to join Dunfermline Athletic, of the Scottish First Division. He scored the winning goal against Stirling Albion on 25 August 2007 and played in Dunfermline's UEFA Cup matches at home 16 August and away 30 August against BK Hacken FC of Sweden. Harper's season was rather inconsistent, though on 25 March 2008 he scored a hat-trick in a re-arranged fixture against First Division strugglers Stirling Albion.
Coaching career
Following the departure of their Under 20s coach, SPFL side Airdrieonians appointed Harper as the replacement in July 2015. He left this post in September 2015. Harper has also set up his own football academy based in Stepps. In November 2015, Thorniewood United manager and former Hibernian team-mate Andy Frame, persuaded Harper to come out of retirement and join the club in a player-coach role. Harper was appointed Albion Rovers manager in November 2018. He became the first black, Asian or minority ethnic manager of a Scottish club since Márcio Máximo in 2003. A struggling Rovers side won none of their first 12 matches under Harper, but then won five of their last nine fixtures in 2018–19 Scottish League Two to avoid relegation. In May 2019, Harper extended his contract with the club to the end of the 2019–20 season. Albion again avoided relegation by finishing ninth in that season, but Harper decided to leave the club at the end of his contract in May 2020. Harper later revealed that, despite having avoided relegation again with a very poor 9th place finish, he had been offered reduced terms, in line with a greatly reduced club budget due to prevailing circumstances, to stay and believed the board could match the ambition he had for the club. In June 2020, Harper appeared in a special podcast panel discussing his experiences of racism in football with A View from the Terrace host Craig Fowler.
