Born in Manchester, Ishmael came through the ranks at Manchester City, signing his first professional deal in 2005. He made a loan switch to West Bromwich Albion at the start of the 2007-08 season. With 7 goals in 21 games, he made a permanent transfer to The Hawthorns in January 2008 for a possible £1.4million fee, leaving City after seventeen senior appearances in three years.
He helped the Baggies win the 2007-08 Championship title, scoring 16 goals in 40 games in all competitions. After playing in the 2008-09 Premier League between August and December 2008, Ishmael suffered a knee ligament injury and missed the remainder of a season which saw West Brom relegated.
Ishmael again helped the club to an immediate top-flight return in 2009-10, finishing as runners-up and securing automatic promotion. A short 93-day loan to Queens Park Rangers preceded Miller's West Brom exit, joining Championship club Nottingham Forest in a £1.2million transfer in August 2011. In two years at the City Ground, Ishmael spent time on loan at Middlesbrough (2012-13) and Yeovil Town twice (2013-14), leaving Forest after just twenty-five games.
Over the course of the next few years, Miller would have short periods with Blackpool (2014-15), Huddersfield Town (2015-16) and Bury (2016-17).
After a period away from the sport, Ishmael signed for League Two Oldham Athletic in August 2018, returning to the game to work for his former Manchester City reserve coach Frankie Bunn, who was then Oldham's manager. However, Bunn was sacked at Boundary Park 27th December 2018 and Ishmael was released from his Latics contract on 3rd January 2019.
Tranmere manager Micky Mellon, seeing the opportunity to sign a player of Ishmael's quality, brought Miller to Prenton Park just four days later, signing the striker on the 7th January 2019 on a contract until the end of the 2018-19 campaign.
Scoring on his debut in a 1-3 victory at Cheltenham Town, Miller suffered a serious injury in just his second appearance for the club in a 1-2 home defeat to Swindon Town on 19th January. Whilst his injury was unfortunate, Ishmael brought a lot to the Tranmere squad — size, power, ability and experience of playing at the highest level and of winning promotions in a 250+ game career.
Miller signed a further 6-month contract on 27th June 2019, allowing him to participate in Rovers’ return to League One in 2019-20.
Interesting Fact: Following his injury, Manager Micky Mellon revealed Ishmael had asked Rovers to reduce his wages as a way to allow the club to find a replacement player.