BOBBY Thomas admits Coventry City need to tighten up at the back ahead of an M69 derby clash against Leicester City. And while Coventry have enjoyed a free-scoring start to the season at the top end of the pitch, Thomas admits the Sky Blues can improve defensively. Thomas said: “The amount of goals we’ve conceded this season have been pretty unfortunate for the pressure and shots we’ve faced. “We’re conceding Championship goals – deflections going into the far corner – we’re not getting opened up but I’m sure it’ll start clicking. Thomas added: “We’ve taken off from last year where we were playing quite nice football towards the end of the season.