Gorkss and Hewitt need replacing
Kaspars Gorkss has departed for Greece so will need replacing at centre half.
And boss Tony Humes will also have to fill a wide midfield slot, with Elliott Hewitt suspended.
The Ipswich Town loanee picked up a red card in last weekend's win against Orient and sits out the first of his three game ban against the Bantams.
Kenny McEvoy is one option for Humes, having signed on loan on Friday afternoon from Premier League side Tottenham Hotspur.
He will be with the U's for the rest of the season, and has already impressed with two goals in the 2-2 draw at Millwall U21s on Monday night.
Alex Gilbey doesn't make the trip to West Yorkshire, still struggling with his ankle injury he picked up in training recently.
Squad: Walker, Lewington, Clohessy, Gordon, Wynter, Eastman, Vincent-Young, Briggs, Harney, Fox, Moncur, Lapslie, Szmodics, Massey, McEvoy, Watt, Sembie-Ferris, Marriott, Porter, Bonne.