U's midfielder David Wright is recovering well after being knocked unconscious at the weekend but will play no part in midweek.
Wright was knocked out just before half-time in Saturday's 3-1 defeat at Notts County and after lengthy treatment on the pitch was stretchered off to hospital, where he was later released following tests.
Physio Tony Flynn told the club's official website: "David is okay now. He went to the hospital and was allowed to leave about 8pm on Saturday evening and travelled back with the rest of the squad.
"We will monitor him carefully. He won't play against MK Dons but we will see how he recovers over the next week or so and then make a decision as to when he comes back into training."
Striker Freddie Sears and winger George Porter returned as second-half substitutes at Meadow Lane after injury and suspension respectively and will be hoping to be involved again.
Centre-back Tom Eastman has recently returned for the club's under-21s after a troublesome ankle injury and could make Joe Dunne's squad, while fellow centre-back Josh Thompson (hamstring) is being monitored.
Stephen Gleeson is expected to return to the Dons squad.
The midfielder missed the defeat at Leyton Orient on Saturday with an ankle injury but should be involved in midweek.
Goalkeeper David Martin remains sidelined with the back injury that has kept him out for the past seven weeks, but the visitors have no fresh injury problems.
Centre-half Antony Kay, wingers Daniel Powell and Luke Chadwick, midfielder Alan Smith and striker Izale McLeod are among those players pushing for recalls.
Kay has not featured for the Dons since receiving his third red card of the season in the 2-1 defeat at Crewe on March 19, while McLeod has not started a game since the 3-2 home loss to Shrewsbury the week before.