 Complete the following phrase:  Blackman joined Chelsea at U13 level and progressed through the clubs youth system. He made his first appearance in a senior match day squad on 29 October 2011, sitting on the bench for a Premier League match against Arsenal which Chelsea lost 35 at home. He began to train regularly with the first team squad in the 201112 season and was an ever-present as Chelsea U18 won that seasons FA Youth Cup. In January 2012 he was also included on the clubs Champions League A-list as a home-grown player, replacing Hilário and allowing Ryan Bertrand to be registered instead as the left-back did not meet the required number of years at the club to qualify as club-grown. This ensured that Blackman received a winners medal after Chelsea defeated Bayern Munich in the 