Arsenal forward Danny Welbeck will be out until after next month's international break with a groin injury sustained against Chelsea on Sunday.
Welbeck will miss Wednesday's Carabao Cup clash with Doncaster, the Premier League games with West Brom and Brighton and the Europa League tie at Bate Borisov of Belarus.
Boss Arsene Wenger told arsenal.com on Tuesday: "Danny has a scan today. We don't know how bad his groin injury is but he will certainly be out until the international break."
Arsenal's first game after the internationals is against Watford on October 14.
Playmaker Mesut Ozil, midfielder Francis Coquelin and full-back Mathieu Debuchy will also be absent on Wednesday.
Midfielder Jack Wilshere played his first Gunners game in over a year in last week's Europa League win over Cologne.
Ozil remains sidelined with the knee problem which meant the German missed the trip to Chelsea.
Wenger said: "Mesut is training again, but for (Wednesday), no (he will not feature). He has a little inflammation of his knee."
Defender Calum Chambers will be included against Doncaster. "It will be a similar team to the one that played against Cologne," Wenger added.
James Coppinger has warned Doncaster not to show Arsenal too much respect as he prepares to renew acquaintances with the Premier League giants after 12 years.
Midfielder Coppinger was part of the team which was denied a Carling Cup semi-final place by the Gunners after a dramatic penalty shoot-out in December 2005, and is relishing Wednesday night's third round rematch in the same competition, now known as the Carabao Cup.
Promoted Doncaster currently sit in 19th place in League One having taken just six points from their first eight games, but will head for the Emirates Stadium determined to make a mark once again.
Coppinger told a press conference: "It's been 12 years since the last game against Arsenal and I'm looking forward to a fantastic night.
"Realistically you have to give them respect because they are a top team - but not too much and hopefully we can catch them out."
Manager Darren Ferguson too is convinced the result is far from a foregone conclusion.
He said: "Everyone is reflecting on the 2005 clash and the only difference is we are at their place. We are going down there to shock them and in a one-off game, you never know.
"To win the game, we have to be bang at it. We have to give an eight or nine out of 10 performance and hope they aren't at it.