J Collin and J Simpson will assist him on the sidelines with S Attwell as the fourth official.Mason officiated just the one United game in the 2008/2009 campaign. That was the Blades' clash with Birmingham City at Bramall Lane - he dished out six yellow cards and handed the Blades a penalty, which David Cotterill dispatched. Two of Boro's games last season was refereed by Mr Mason.