Phil Parkinson has warned his Bradford City side of the dangers posed by Jermain Defoe - labelling the striker as Sunderland's "jewel in the crown" ahead of Sunday's fifth-round clash.
Defoe has scored twice in five appearances for Sunderland since moving from Toronto FC last month and is likely to feature against City at Valley Parade.
If City - conquerors of Chelsea in the last round - are to knock out Premier League opposition again this weekend, Parkinson feels Defoe needs to be stopped.
"I've seen two of their last three games and you've got to say Defoe is the jewel in the crown at the moment," Parkinson explained on Friday.
"His movement in the box is exceptional, that's why he has such a good goalscoring record. We're going to have to make sure our concentration levels are right.
"Can we stop the balls coming and, when it's in the box, we have to concentrate until the end."
Much of the build-up to this weekend's tie has centred on comments made by Sunderland boss Gus Poyet - who described the Valley Parade pitch as "one of the worst in the country".
Parkinson, who was also critical of the surface recently before retracting his comments, added: "We want the pitch to be in the best condition it can be as we've got some good footballers but whatever the state of the pitch is we've got to try and be the best team on it.
"Anyone who saw the game [against MK Dons] on Monday, saw some great football played - I don't think it's as bad as people make out.
"We're going to look forward to the occasion but when the whistle blows it's important that we focus on the factors that will give us the best chance.
"We've got to take confidence from the Chelsea victory and the lads are in a confident state of mind on the training ground.
"But we've also got to go into the game with an underdog mentality - to put into perspective one of their mid-earners will be earning more than our whole squad put together.
"There's a huge gulf but my job and the rest of the coaching staff is on Sunday to make sure the gulf isn't that evident and that's what we'll try to do."
