After only one year at Arlesey, Blackett and teammate Craig Mackail-Smith signed for Conference National side Dagenham & Redbridge at the beginning of the 2004–05 season.
[3] After two seasons of finishing with Dagenham in mid-table, Blackett played a part in the Daggers' promotion-winning campaign of 2006–07, but was sold to Peterborough United in the January transfer window, again alongside Mackail-Smith.
[4] Over the next two seasons, Blackett played in both of Peterborough's back-to-back promotions making a total of 35 league appearances, although he struggled with injuries.
[10] In December 2013, Blackett left Arlesey to join Hemel Hempstead Town, and he helped the club win promotion to the Conference South for the first time.
[11] Blackett then joined Dunstable's league rivals, fellow Southern Premier Division side St Neots Town, in October 2015.