Tommy Rowe felt Rovers should have taken something from the game after losing to a last-minute Josh Ruffels strike away at Oxford in Sky Bet League One.
Rovers looked to have secured a point on their travels until deep into stoppage time, and Rowe believes that was the least they deserved.
He said: "Its bitterly disappointing, we really pushed on after half-time and started on the front foot.
"Ian Lawlor saved the penalty and we looked to have earned a point away from home but it wasn't to be.
"In the latter stages we would have probably taken a point, there is a mix of emotions in the dressing room."
Rowe hit a post and forced a good save from U's goalkeeper Simon Eastwood with the game at 0-0, and says he wants to add more goals to his game in the near future.
"The manager encourages me to shoot from distance and that's something I'm always working to try and improve on," he added.
"They gave us a lot more room in the final third than we thought we would have so we got some good chances.
"The ball rolled across the line when I hit the post which was unlucky but all I can do is keep getting in those areas."
Rovers return to the Keepmoat Stadium to face Oldham Athletic on Saturday December 16. You can purchase tickets from the Club Doncaster Box Office on 01302 762576, or at tickets.clubdoncaster.co.uk.