Complex sentence: After ridding himself of the injuries that had stopped his progress over the last 2 years, Riley joined Oxford United on loan on 28 July 2014, he returned to Bolton on 3rd January 2015 after 28 appearances in total (22 league) for Oxford.
Split into simpler sentences: After ridding himself of the injuries that had stopped his progress over the last 2 years, Riley joined Oxford United on loan on 28 July 2014. He returned to Bolton on 3 January 2015 after 28 appearances in total (22 league) for Oxford.