in League One. He was subject to an offer by Hibernian in January 2012, but remained in England. On 3 March, he was sent off after retaliating to a foul by Craig Eastmond in a 4–1 victory over Wycombe Wanderers at Glanford Park. He was released by the club in May 2012. Rotherham United O'Connor signed a two-year contract with Rotherham United in May 2012. He made his "Millers" debut on 18 August 2012, in a 3–0 win over Burton Albion at the New York Stadium. He scored his first goal for the club in 4–0 win over Bradford City on 1 September. He scored again the following week in a 6–2 defeat to Port Vale. On 29 September, he scored twice in a 3–1 win against Oxford United. On 9 February, he was sent off for a stamp on Jacques Maghoma in a 2–0 defeat at Burton Albion. On 15 December, he was named in the League Two team of the week for his performance in a 1–0 win at AFC Wimbledon. In all he scored six goal in 40 appearances as he helped Steve Evans's side win promotion out of League Two. He made 34 appearances in the 2013–14 campaign, helping the club to reach the League One play-off final. He was an unused substitute at Wembley Stadium as Rotherham secured promotion with a penalty shoot-out victory against Leyton Orient. He was released by the club in May 2014. Port Vale O'Connor signed a one-year contract with League One club Port Vale in July 2014. He scored his first goal for the club on 26 August, hitting the net from 40-yards out in a 3–2 League Cup defeat to Cardiff City at Vale Park; this was one of the longest distance goals ever scored by a Vale player, and won him the club's Goal of the Season award. Despite this effort the local newspaper reported that generally throughout the campaign "his contribution is industrious and effective without grabbing the headlines". At the end of the 2014–15 season he was named as the club's Player of the Year, and also won the Supporters' Club's Trophy and was voted Players' Player of the Year. He signed a new contract with the club in June 2015. He picked up a knee injury in 2015–16 pre-season training, and had to wait until October before returning to match fitness. He then lost his