Lee Cattermole made his Wigan Athletic debut in last night's 6-0 friendly win at Barnsley.
King got the ball rolling on eight minutes, pouncing on a rebound before Heskey hit a low strike past goalkeeper Kyle Letheren.
Valencia made it 3-0 in the 26th minute with an excellent finish, and De Ridder grabbed his first of the game just after the break courtesy of a deflection.
De Ridder was then on target on 51 minutes but he missed an opportunity to net his hat-trick when he saw a spot-kick saved by Letheren.
Brown completed the rout with five minute remaining, heading home from close range after substitute David Cotterill had seen his shot saved.