Canterbury signed Potter while he was still a student at St. Gregory's, Campbelltown. He made his first grade debut in the round 18 match of 1983 against Eastern Suburbs coming in for the injured Neil Baker. Interestingly there were 3 referees used in this match when the appointed referee, Mick Stone was injured. He was replaced by the reserve grade referee, Lionel Green, who subsequently was replaced by the Third Grade referee Paul Miller. This was Potter's only game of first grade in 1983. In only his second year of first-grade, Potter became the first fullback to win the Dally M Player of the Year award. He is a member of Canterburys' 1984 Premiership winning team in their 6-4 win over Parramatta. A second premiership followed when Canterbury defeated St. George, 7-6 in the 1985 Grand Final at the Sydney Cricket Ground. Potter broke his leg in 1986 and struggled to regain his form at Canterbury.
St. George Dragons
He signed with the St. George Dragons in 1989 and later became team captain. In 1991, Potter won his second Dally M Player of the Year award. He played fullback for the Dragons in the 8-28 Grand Final loss to the Brisbane Broncos in 1992.
Michael Potter's good form for the Dragons in the back half of the 1992 season saw him in contention for Australia's World Cup Final squad as incumbent Aussie fullback Andrew Ettingshausen was unavailable because of injury, as were Gary Belcher and Dale Shearer. However, the size of the loss to the Broncos may have cost him his chance with Balmain's Tim Brasher and Newcastle's Brad Godden selected for the fullback role instead.
The following season Potter was captain of St. George in their 6-14 loss to Brisbane in the 1993 Grand Final.
Potter retired at the end of the 1993 season but signed to play for one of the four new teams introduced for the 1995 season, the Western Reds, going on to play 21 games for the Perth based team before retiring for good at the end of the 1996 ARL season.
Following his retirement as a player in 1996, Potter started his coaching career as assistant coach for the English Super League team, Bradford Bulls, alongside Matthew Elliot. He remained there until 1999 when he took over the coaching position for the New South Wales Under-17 squad, coaching them to consecutive wins over Queensland.
Potter coached St. George Illawarra's Premier League side for four years before being appointed in February 2006 as Head Coach for the French rugby league team Catalans Dragons, succeeding Steve Deakin. Potter coached the team to the 2007 Challenge Cup Final and in 2008 was named Super League coach of the year.
Potter succeeded Daniel Anderson as head coach of St. Helens at the beginning of the 2009 season.
In May 2010 he announced that he is to leave St. Helens at the end of the 2010 season. In July 2010 Potter signed a 2-year contract to return to Bradford Bulls, this time as head coach, commencing 2011. Despite the club being placed in receivership in 2012, the team was on the verge of making the semis as Potter remained as unpaid coach. "I think I served above and beyond what I needed to do there," Potter said . "I felt obliged to do that. It has made me a better coach. The reasons I want to coach aren't financial but because you love the game."
In October 2012, NRL team West Tigers confirmed that Mick Potter would be the head coach for the 2013 and 2014 seasons. With papers reporting that he had been endorsed by the club's players, Potter said, "I am very happy to be here, there's not many jobs like this. I have served a long apprenticeship and I think I am ready."
After much speculation during the 2014 season, following reports of miscommunication between him and the playing group, as well as continued poor results on the field, Potter was sacked as Wests Tigers coach on 17 September 2014.
Potter spent a large part of 2015 coaching the Fijian under-20s side, and was an assistant coach with the New South Wales under-16s team. In November, it was confirmed that he would be joining the Newcastle Knights as an assistant coach under Nathan Brown.
In 2016, along with his role as assistant coach at the Knights, Potter became the new coach of the Fiji national rugby league team on a deal to the end of the year that would see him coach Fiji in the 2016 Pacific Test against Papua New Guinea, with the Fiji National Rugby League and Potter, at the end of the year, to discuss extending that into the 2017 Rugby League World Cup.