Michael Carrick has revealed why Alex Gilbert missed Middlesbrough’s defeat to Sunderland on Saturday. Boro fell to a 1-0 defeat in the Tees-Wear derby, continuing their run of failing to win two consecutive games at the Stadium of Light since 2006. The visitors started the brighter of the two but Tommy Conway and Matt Clarke both missed great chances. Neto Borges and Isaiah Jones both struggled and the former played a role in Sunderland’s goal, scored by youngster Chris Rigg. Michael Carrick reveals extent of Alex Gilbert injury Although Gilbert’s role is largely bit-part within the Boro firs…