the form of Matt Richards and loan signing David McAllister again left him sitting on the sidelines for much of the season. Shrewsbury won promotion to League One as runners-up of League Two, although McAllister was not offered a new contract. He said that "Hopefully my experience at a higher level, and the fact that I've got a promotion under my belt, will help my cause. I'm disappointed, I thought I was worth a new deal, but I've had two good years at Shrewsbury." Port Vale McAllister failed to find a club before the start of the 2012–13 season, despite a trial at Oxford United. In October 2012, he went on trial at Port Vale, after personally ringing manager Micky Adams to enquire about a vacancy in midfield created when Doug Loft picked up an injury. He signed an eight-week contract with Vale on 9 November. The League Two club were in administration, and applied for special permission to sign McAllister after asking the Football League for leniency after they underwent a shortage of available midfielders. He made his debut from the bench at Vale Park on 17 November, replacing Rob Taylor 74 minutes into a 2–2 draw with York City. However, he would only feature twice more for Vale, and left the club on 8 January 2013, with Adams saying "it's unfortunate we weren't able to offer Sean more first-team opportunities, but that underlines the competition for places we have among the squad, but he's a great kid, a model professional and I'd recommend him anywhere." Cowdenbeath McAllister joined Scottish First Division club Cowdenbeath in March 2013. He made nine appearances at the end of the 2012–13 season, helping the club to avoid relegation. Scunthorpe United On 19 July 2013, McAllister made a return to League Two when he signed a one-year contract with Scunthorpe United. He made 43 appearances in the 2013–14 season as Scunthorpe won promotion as divisional runners-up, and was also crowned the club's Player of the Year for his "high energy and consistent performances". He signed a new two-year contract in May 2014. However, after Mark Robins replaced Russ Wilcox as manager, McAllister found first-team football hard to come by in the second half of the 2014–15 season. He made 15 appearances across the 2015–16 season, and was released at the end of the season. Grimsby Town On 23 June 2016, McAllister signed a two-year