Bradford City manager Phil Parkinson has described Jermain Defoe as the "jewel in the crown" of Sunderland's side ahead of the FA Cup fifth round.
The League One side knocked Chelsea out in the last round to set up the meeting with Gus Poyet's side this weekend.
At his pre-match press conference, Parkinson said: "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.
"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."
Defoe has scored twice in six appearances since joining the Black Cats in January.
