After accomplished displays in the
FA Cup, most notably against
Swansea City and
Watford in January 2007, Casement moved out on loan to
Millwall for three months. When he did finally join Millwall, he did not make an appearance during his month there. In August 2008, he signed on loan with
Hamilton Academical until January 2009. Chances were limited for Casement, and he returned to Ipswich having mainly been used as a substitute. On 7 January 2009, Casement signed on loan for
League Two side
Wycombe Wanderers for a month. This loan deal was subsequently extended, firstly to two months, then to three months. Casement returned to Ipswich before being released on 8 May. On 22 June, it was announced that he had signed a three-year deal with
Scottish First Division side
Dundee. On 31 January, Casement signed on loan for
Linfield until the end of the season. On 4 May 2010, he was informed along with three other players that he was no longer wanted by Dundee and was free to look for another club. On 8 May 2012, it was confirmed Casement had signed a three-year contract with
Portadown. On 26 July 2016, it was announced that Portadown had accepted a bid in the region of £20,000 for Casement and it was announced later that he would be rejoining the
Blues on a two-year contract. On 30 September 2020, Casement signed for
Stowmarket Town. He was appointed manager of the club in February 2023. In May 2023, he stepped down as manager to focus fully on the continuation of his playing career. In June 2023, Casement joined
Leiston. In June 2024, Casement joined Isthmian League North Division side
Ipswich Wanderers. ==International career==