William Collum will take charge of Thursday's Europa League quarter final clash between Valencia and Villarreal. 

The Scotsman will be the man in the middle for the second leg encounter between the Spanish sides at the Mestalla, as the two vie for a spot in this year's semi finals. 

Valencia hold a 3-1 aggregate lead heading in to their home fixture this week, and a team of Scottish officials will oversee what is one of the biggest fixtures in European football. 

Willie will be accompanied by Assistant Referee's David McGeachie and Frank Connor, with Graeme Stewart selected as Fourth Official. Bobby Madden and Nick Walsh are on Additional Assistant Referee duties. 

AR1: David McGeachie
AR2: Frank Connor
Fourth Official: Graeme Stewart
AAR1: Bobby Madden
AAR2: Nick Walsh