Michael Appleton is sweating on the fitness of two players ahead of his first match as Oxford boss against Burton.
Captain Jake Wright missed their friendly defeat to Bournemouth on Saturday with an ankle injury while Johnny Mullins' dead leg saw him also sidelined and the pair are rated as 50/50 to tackle the Brewers.
With goalkeeper Ryan Clarke set to miss the opening weeks having undergone a foot operation Sheffield United loanee George Long will make his U's bow.
There could also be debuts for the likes of Junior Brown and Norwich loanee Carlton Morris as Appleton looks for the perfect start to life in the Kassam hotseat.
Burton look to have a clean bill of health.
Last season's Sky Bet League Two play-off finalists have strengthened with the addition of several players over the summer and Albion boss Gary Rowett could hand debuts to most of the new arrivals.
Shane Cansdell-Sherriff, signed on a permanent deal during the close season after his successful loan spell at the Pirelli Stadium, is likely to be partnered in central defence by former Leicester youngster George Taft.
Lucas Akins will probably start while John Mousinho, Stuart Beavon and Callum McFadzean, back at Burton for a second loan spell, will also hope to force their way into Rowett's plans.