At the young age of 16, Andy Pettinger was promoted to the first team setup at Scunthorpe United, albeit at the time, as the club's 4th choice goalkeeper, in a keeper line-up that consisted of Tommy Evans, Ross Turner and Leigh Herrick.
In September 2002 Andrew left the club after suffering from homesickness, so he returned home to his native Lincolnshire to sign with his former club Scunthorpe's local rivals, having signed a one-year contract with Grimsby Town. Pettinger would become the second choice goalkeeper during the 2003–2004 season. Pettinger deputised three times for Aidan Davison throughout the season. Davison was eventually ruled out of the last three months of the season, but the club instead chose to loan in Alan Fettis from Hull City instead of letting Pettinger take over. This decision came despite Pettinger playing notably well when called upon, amongst his games included a 6–1 derby day victory over Barnsley. Following Grimsby's relegation from the Second Division, Pettinger was amongst those players released.
Armthorpe Welfare
At the start of the 2005–2006 season, Pettinger moved even further down the non-league game by signing for Yorkshire amateurs Armthorpe Welfare. In 2006, Armthorpe granted permission for Pettinger to join Football League One side Oldham Athletic on trial, but following a week training with the club he failed to earn a contract. Pettinger left Armthorpe eventually at the end of the 2008–2009 season.
Brigg Town
Pettinger made a third return to Lincolnshire this time signing with Brigg Town at the start of the 2009–2010 season.
Gainsborough Trinity
In May 2011Brian Little signed for his Conference North side Gainsborough Trinity bringing him to the club as understudy to Phil Barnes several weeks after Brigg manager Steve Housham had been appointed as Trinity's new youth team manager. Pettinger served as the second choice keeper under Phil Barnes during the 2011–12 season, but briefly replaced an injured Barnes until Pettinger himself was sidelined with an injury that ruled him out for the remainder of the season. At the end of the 2011–12 season he left Trinity to concentrate on his part-time coaching work with Scunthorpe United.
Return to Brigg
After one year out of the game, Pettinger returned to playing by signing for Brigg at the start of the 2013–14 season.