sentences:  In August 2013 Holster signed for Azerbaijan Premier League side Ravan Baku.On 19 October 2013, Holster made his debut for Ravan Baku, coming on as a half time substitute for Miloš Adamović in their 2-1 defeat to Neftchi Baku.Holster left Ravan at the start of the winter break in December 2013, and went on to sign a two-year contract with Assyriska in March 2014.