Stoke City boss Tony Pulis admits Manchester United manager Sir Alex Ferguson will be pleased seeing the Potters having played three games in six days.
Stoke go into their clash with United on the back of a gruelling schedule.
"Sir Alex will be rubbing his hands," Pulis said.
"The only thing I will say is how good our 15,000 supporters were and I hope 28,000 will turn up on Saturday because we really, really need them to get behind the lads."
Saturday is also when the draw for the last 16 will be made and Pulis is hoping to land another home tie as the Potters look to return to Wembley after last season's FA Cup semi-final and final appearances there.
"We'll take anyone at home, anybody at the Brit," he said.
"It's the last 16 now, so it gives us a chance again."
