[4] He made his debut for the Parramatta Eels coming off the bench in round 1 up against St. George Illawarra, but only to suffer a horrific hamstring injury immediately ending his season.

[5] After suffering one of the worst hamstring injuries seen by doctors, Shackleton had worked hard to get back into the side and was a regular off the bench for Parramatta.

"[7] Soon after, Shackleton signed a two-year deal to link up with the Penrith Panthers prior to the 30 June trade deadline, resulting in an immediate switch to the new club.

In 2013, Shackleton was working part time as a labourer and also a comedian while playing for the Mount Pritchard Mounties in the Intrust Super Premiership NSW competition.

[9] In November 2018, Shackleton played for Parramatta in the Legends of League tournament which was staged at the Central Coast Stadium in Gosford.