Duo missing for U's
Oxford will be without key duo James Constable and Jake Wright for their top-of-the-table clash with Chesterfield.
The second-placed U's welcome the Sky Bet League Two leaders without striker Constable, who has chipped a bone in his foot, and Wright who has undergone an operation on a groin problem.
Both players are set to be sidelined for at least a month and they join Jon Meades in the treatment room.
In Wright's absence it means Johnny Mullins will be partnered by Michael Raynes while Deane Smalley is pushing for a start. There is positive news about Sean Rigg who hopes to return to training in the build-up to the clash.
Chesterfield have no new problems ahead.
Blues boss Paul Cook, who will still be without defenders Nathan Smith (ankle) and Matty Brown (hamstring), must decide whether to make changes to a winning team after seeing the Spireites stretch their advantage at the summit of Sky Bet League Two to four points with a 2-0 home success against AFC Wimbledon last weekend.
Gary McSheffrey made his debut from the bench and will be pushing for a start along with fit-again club captain Ian Evatt and in-form striker, in the reserves at least, Eoin Doyle.
The likes of Sam Togwell, Armand Gnanduillet and Ryan Edwards are also options for Cook.