Derby midfielder George Thorne could make his first appearance of the season after recovering from a knee injury.

However, top scorer Chris Martin, who has 19 goals this season, is ruled out with a knee problem.
For Reading, midfielder Danny Guthrie has recovered from a groin injury and returns to the squad.
Striker Yakubu, who joined the club in January, is available despite breaking his nose in a 2-0 defeat at home to Leeds on Tuesday.

MATCH PREVIEW

Reading manager Steve Clarke is hopeful his team can record a surprise win against a Derby side challenging for the Championship title and promotion to the Premier League.
"We know how good Derby are because they have already beaten us twice this season - in the league and Capital One Cup - so we are expecting a tough game," he said.
"But we have a good squad too and we have worked hard to get to this stage. It's been a cup of shocks this season and if we went to Derby and won it would also be classed as a shock."

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"Derby are going for automatic promotion to the Premier League but I think Rams boss Steve McClaren will see the FA Cup as a chance to keep their good run going rather than a distraction."
Predictions:

Derby boss Steve McClaren, whose side are one point behind Championship leaders Middlesbrough, is considering rotating his squad before a busy period.
"All will be revealed on Saturday but we will make some changes," he said.
"We have three games a week until the early stages of March. Whoever plays though, they will be going out there to win. We like the cups and they've been good to us and we want to get into the quarter-finals."

MATCH FACTS

This is the eighth straight home draw for Derby; the Rams have won four and lost three of the previous seven.
Derby have never played Reading in the FA Cup and have only won 10 of the 36 meetings in other competitions (drew six, lost 20).
Reading have failed to score in their last three matches against the Rams, two of which have been played this season as they met in the Capital One Cup and once so far in the Championship.
Darren Bent has scored in eight of his last nine FA Cup starts including the last six in a row.