Middlesbrough left-back Hayden Coulson has joined League One side Blackpool on loan for the rest of the season. The 25-year-old who came through the Boro academy system featured in the club’s F.A Cup clash against Aston Villa on Saturday. Michael Carrick brought him on in the closing minutes of the match but has decided that he is not needed for first team duties for the rest of the campaign. The club’s website announced via Twitter that Coulson joined up with Blackpool on Monday morning. It will be of little surprise to most Boro fans that Carrick has taken this decision, given the emergence …