Jimmy Nicholl followed Calderwood when he took over as manager at Aberdeen, again serving as his assistant until the two parted company with the club in May 2009. He resumed his partnership with Calderwood at Kilmarnock in 2010. Nicholl was appointed manager of Cowdenbeath in June 2010, but he left Cowdenbeath at the end of the 2010–11 season after they were relegated from the First Division. Nicholl was then appointed assistant manager of Kilmarnock for a second time, by Kenny Shiels on 15 June 2011. Kilmarnock won the 2011–12 Scottish League Cup under Shiels and Nicholl, but Shiels was sacked by Kilmarnock
Dean Shiels to join Rangers. He scored a goal, as well as, setting up two goals in his first appearance, in a Scottish League Cup tie against East Fife on 7 August. A week after he sustained an injury during a match which ruled him out for weeks, On 2 September 2012, Shiels scored his first league goal, as well as setting up a goal, in a 5–1 win over Elgin City. After scoring two goals in three games, Shiels scored against the Scottish Premier League side Motherwell, in a Scottish League Cup tie. Then, in the Scottish Cup, Shiels scored twice