There are reunions that players relish. Alexander Isak’s return to St James’ Park on Sunday will not fall into that category. Newcastle supporters will make their feelings known and there is little he can do to influence that. His task is simpler. Concentrate on becoming the player Liverpool believed they were signing, and begin winning over those fans now watching him in red. This Premier League opener arrives one year after the statement that detonated his Newcastle exit, with Isak declaring that the relationship cannot continue because of broken promises and eroded trust. Twelve months on, his Liverpool career has yet…