Millwall manager Kenny Jackett admit Crystal Palace have done well to keep hold of Wilfried Zaha.
The Eagles forward has been linked with Arsenal, Liverpool and Manchester City in recent weeks.
"He got two goals against Burnley [on October 6]," Jackett said. "They've done very well to hold him.
"He is a big player for them and we have to do our homework and negate him as much as we can without taking away our strengths to go on and win the game."