Downey started his career as a trainee at Hartlepool United in 1997 but in three years with the club he had failed to make a single first team appearance and was released in 2000.
He had struggled to make an impact with The Seadogs, and following his release in 2004 he was surprisingly signed up for Football League Two side Grimsby Town by Russell Slade, his manager at Scarborough.
Originally signed as defensive cover, he was given a new one-year deal a year later despite the fact he only played 14 minutes in his first season with The Mariners.
In his only league appearance of that season on New Year's Eve, he came on as substitute and scored an 84th-minute winner against Wrexham in a game where both Grimsby centre backs Simon Ramsden and Rob Jones departed through injury.
Despite earning several plaudits in all 3 of his appearances for the club, Downey was released and joined Conference North side Worksop Town at the start of the 2006–07 season.