George Williams admitted the Dons dressing room was a downbeat place after drawing 1-1 with Port Vale on Monday.
The 26-year-old defender made his return to first team action for the first time since January on Good Friday, but saw Kieran Agard miss a first half penalty and Chuks Aneke hit the post when through one-on-one late in the day as Dons slipped out of the automatic promotion spots with two games to go.
Tom Conlon opened the scoring just three minutes into the second period, but David Wheeler equalised within four minutes. Aneke then squandered his chance with a few minutes to go, meaning Bury's win over Northampton means Dons dropped to fourth.
"It's a little bit flat at the moment, it's going to be," said Williams afterwards. "But we're a good group. We'll dissect it, talk about it in the dressing room. But there's nothing we can do, we've just got to look at the Colchester game, regroup and go again.
"We should have won it, we had a few good chances. But we started the second half a bit flat, and it killed us a bit.
"It was frustrating. It's hard to put our finger on it. It feels good to be back, but the feeling of coming off without three points is frustrating. I'd much rather be here with three points."
With the season now going down to the final day of the season - the home clash with Mansfield - Williams said he has not allowed himself to think that far ahead yet, concentrating on the trip to Colchester next Saturday.
He said: "I haven't even thought about it. We've got to give ourselves the best chance possible on the final day. That means going to get three points next week, then whatever else happens, happens."