The Royals will be forced into making changes for tonight's second leg match with Burnley, kick off 7:45pm, and Steve Coppell has plenty of options available to him.
Andre Bikey serves the first game of a four-match ban, while Kevin Doyle is set to miss out with an Achilles problem.
Alex Pearce and Kalifa Cisse are in contention to replace Bikey, although Coppell suggested he could play someone out of position as Burnley will likely play one up front.
Dave Kitson is in line to start if Doyle misses out, and one or both of Simon Church and David Mooney could therefore be on the bench. Leroy Lita is in training but not quite fit.
Coppell said, "At the back I have options, there's Pearce, Cisse and others. Given that Burnley probably won't change shape and have a nippy striker [Paterson] up front, perhaps we won't have the need for a big central defender and we can field a smaller defender in there.
"The chances are we will go 4-4-2, it's our responsibility to take the game to them. We're more comfortable playing that way so chances are we'll change it.
"It's a bit too early for Lita at the moment; he has only trained twice so I would say it's asking a lot."
Chris Armstrong, James Harper, Noel Hunt, Ivar Ingimarsson and Graeme Murty are all out.
Burnley await news on midfield trio Wade Elliott, Chris Eagles and Joey Gudjonsson.
Tickets for tonight's game are on general sale to all Member Card holders right up until kick off. Telephone 0844 249 1871, use the online ticketing service or visit in person.
