Full back Chris Latham and centre Sam Tuitupou are both set to feature after making full recoveries from injuries sustained last season.
George Dixon, Calum MacRae and Ed Binham, all currently on trial at Sixways, are also selected with Ruddock aiming to rotate his team at half-time and give the majority of his first team squad some game time.
Tickets are available on the night for just £5 and will gain supporters admittance to the stadium with selected stands open.
Season Ticket holders and Debentures will gain free entry to the game.
Fans are advised that the Park and Ride system will be in operation tomorrow night and also for the Ulster Rugby game on Friday, August 28.
Worcester Warriors v Doncaster Knights:
Jonny Arr, Miles Benjamin, Ed Binham, Adam Black, Joe Carlisle, James Collins, Matt Cox, George Dixon, Charlie Fellows, Chris Fortey, James Freeman, Ollie Frost, Marcel Garvey, Rico Gear, Jack Gilding, Craig Gillies, Alex Grove, Graham Kitchener, Chris Latham, Aleki Lutui, Dave Lyons, Calum MacRae, Dale Rasmussen, Greg Rawlinson, Shaun Ruwers, Tevita Taumoepeau, Sam Tuitupou, Willie Walker, Tom Wood