On-loan Arsenal keeper Wojciech Szczesny and Ipswich centre-half Tommy Smith are ineligible for Brentford.Mark Phillips or Alan Bennett will come in at the back, Lewis Price keeps goal, John Bostock's loan from Spurs could be extended and Sam Saunders faces a test.
Doncaster skipper Brian Stock is expected to continue despite being withdrawn with cramp on his comeback from ankle surgery on Saturday.
Martin Woods returned to full training last week but is not ready to feature.
BIG-MATCH FACTS
The tie in context
• Brentford are one of five League One clubs still in the competition; Doncaster are one of 13 remaining representatives from the Championship.
Gulf in class
• Doncaster are 22 places superior on the league ladder.
Fourth Round draw
• Prize for the winners is an away trip to Championship club Derby.
Head-to-head
FA Cup records and best performances
• Doncaster are meeting Brentford for the 50th time in a competitive match.
• The south Yorkshire club have won their last four clashes, and not lost in six, keeping clean sheets in all of them.
• They have not met since the 2006/07 season, when they faced each other three times.
• That included a 1-0 win for Rovers in the first round of the FA Cup at Griffin Park, when Lewis Guy scored the winner.
The clubs
BRENTFORD
Current form
• Brentford are undefeated in five (W3, D2).
• The Bees are looking for a 10th home game without loss.
• They have won five and drawn four on home turf, since losing to Swindon by the odd goal in five on 3 October.
FA Cup form
• The Bees have not been this far in the cup, since reaching the fifth round in 2006.
• They knocked out Premier League Sunderland on their way to the last 16 four seasons ago.
DONCASTER ROVERS
Current form
• Rovers have won six of the last eight - all Championship games.
• Saturday's 2-1 home win over Watford was their first match since Boxing Day, and followed four consecutive postponements.
FA Cup form
• Rovers made the fourth round for the first time since 1985 twelve months ago.
• They have not lost to lower ranked opposition, since Exeter in the second round in December 2004. The Grecians were then in the Conference and Doncaster in League One.
Replay date
Saturday, 23 January (Kick off: 1500)
Match officials
Referee: Grant Hegley (Hertfordshire)
Assistant referees: Lee Betts & Sian Massey
Fourth official: Warren Atkin
Source: BBC Sport
Source: BBC Sport