Karl Robinson felt the manner of Oxford’s defeat at Doncaster hammered home the need for new additions in the transfer window.
Oxford were beaten 1-0 at the Keepmoat Stadium, suffering only their second defeat in 16 matches, despite dominating large swathes of the game.
And Robinson said signings in advanced areas are a must in January if his side are to maintain their strong push for promotion.
He said: “I think it is glaringly obvious what we need right now. We don’t have any wide players. I wanted some in the summer. We know what we need.
“We want to get deals done sooner rather than later. The things we’ve got lined up short term are exciting.
“I know the board want that to happen but we’ve got to be forceful in this transfer window. We’ve got to act like a big club, not just talk like one.
“Every one of my players put everything into this game and they could not have done any more.”
Robinson was pleased overall with his side’s performance but bemoaned the lack of threat in the final third.
He added: “We dominated that game. We dominated possession, we dominated shots, we dominated set pieces in the final third.
“We’ve hit the post and had two cleared off the line. On another day, if our finishing was better, it could have been a completely different game. But it wasn’t meant to be.
“What we could control, we controlled and it was just a bit of luck that it didn’t drop for us.”
Rovers found themselves under pressure for long periods of the clash but went ahead through Reece James in the first half and soaked up pressure well.
Oxford started the stronger and should have been ahead early on when Matt Taylor was presented with a free header but sent it wide.
Doncaster settled into the game and took the lead after 34 minutes.
Full-back James latched onto a flick from Niall Ennis and lashed a shot into the far corner from a tight angle.
Oxford saw an effort cleared off the line after a Taylor header spun off the post.
And Joe Wright hacked clear for Rovers after the striker slammed a loose ball on goal from 15 yards.
Doncaster boss Darren Moore declared himself satisfied after his side battled their way to victory against what he termed the best opposition they have faced this season.
“It’s satisfying for us because we feel as a group that Oxford are an exceptional team,” Moore said.
“Karl has got his team set up and they play fantastic football and ask a question.
“We had less than 48 hours to prepare for this one so a lot of work was done in the classroom.
“In terms of that I thought the team got the tactics absolutely spot on.
“For Reece James to pop up and get the goal was great but the game was won then with the work off the ball.
“I thought everyone to a man was absolutely key to it and it’s resulted in us winning the game.
“They are the best team we’ve played and credit to them.
“I would imagine they would be there or thereabouts come the end of the season.”