On November 5, 2013, Barker signed a one-year deal with Barys Astana of the Kontinental Hockey League (KHL). After spending the 2013–14 season in the KHL, Barker returned to North America and attended training camp with the Blackhawks on a player tryout offer. However, on September 27, 2014, the Blackhawks announced that they had released Barker, leaving him as an unrestricted free agent. On December 22, 2014, Barker signed a contract until the end of the 2014–15 KHL season with HC Slovan Bratislava, and then had his contract renewed for the 2015–16 season. He left Bratislava after two years to return to Barys Astana in May 2016.