Rivals in the Championship are thought to have been interested in the 25-year-old, with Leeds United linked over recent weeks.
Preston are reluctant to sell but could have their resolve tested before the January window closes, with Palace set to put in a bid for the forward who has scored 10 goals in 29 games this season.
Eagles boss Roy Hodgson is eager to bolster his attacking options at Selhurst Park and Palace are hoping they can push through a deal for Hugill before the window shuts on Wednesday.
Uwe Rosler was sacked by Fleetwood following a 3-0 reverse at Doncaster which condemned Town to a seventh straight defeat in all competitions.
Cambridge interim head coach Joe Dunne was pleased with how his side adapted to beat Grimsby 3-1.
Southend manager Chris Powell led the applause for Jason Demetriou after the right-back scored twice in the 3-1 win against Portsmouth at Roots Hall.
Morecambe boss Jim Bentley was the happier manager after Gregg Wylde's 90th-minute strike earned his side a point in their 1-1 draw with Forest Green.
Manager Gareth Ainsworth described Wycombe's 2-0 win at Cheltenham as a thoroughly professional performance.
Skipper Richard Wood scored the winner just before half time as in-form Rotherham pulled off a 1-0 victory at League One leaders Shrewsbury.