[1] Hackett managed Longford's senior footballers between 1987 and 1990,[2] taking the role at the age of 26.
[1][3] The GAA gave him a postgraduate scholarship in 1992, which Hackett used to obtain an MA in Sports Psychology from the University of Limerick.
[4] He also worked as a sports psychologist with Team Ireland's boxers and sailors at the 2004 Summer Olympics.
[1] In the midst of this, Hackett was chief executive officer of Athletics Ireland from October 2005 until his resignation in January 2008.
[7][8] Hackett included Michael Carruth as a masseur and Eoin Rheinisch as part of "physical preparations" on his backroom team.
[8] Hackett later managed the Kildare minor football team, where his players included the actor Paul Mescal.
[17] In 2022, still managing Ballymun, Hackett was reported to have been interviewed for the Monaghan senior football team's managerial vacancy that arose following Séamus McEnaney's departure.