By Josh O’Brien Philippe Coutinho certainly can’t say he wasn’t warned that leaving Liverpool was a mistake, but ended up finding out the hard way in 2018. After establishing himself as one of the most sought-after playmakers in world football, Barcelona eventually came knocking and the Brazilian’s head was turned. Despite Liverpool’s best efforts, not even they could turn down the astronomical £142million transfer the Blaugrana were offering in the January transfer window. From Coutinho’s perspective, he was walking away from a lot. The Anfield faithful adored him, he had the backing of boss …