Complex sentence: Robson did not appear for first day of the 2013 season's training camp on 21 January 2013 and, shortly afterwards, the team announced that the two sides had mutually agreed to terminate Robson's contract.
Split into simpler sentences: Robson did not appear for first day of the 2013 season's training camp on 21 January 2013. Shortly after, the team announced that the two sides had mutually agreed to terminate Robson's contract.