Lionel Ainsworth has returned to Watford so they can access the injury to his knee sustained last Saturday when playing for Hereford United against Northampton.
"Losing Lionel is a bitter blow," said manager Graham Turner.
"He will miss tonight and I think that he could miss quite a few games.
"He jarred his knee in a tackle and hopefully we will have some more news in the next 24 hours."
As regards the game Turner commented:
"We know that MK Dons are a good side. The report we got back from their win at Walsall on Saturday said as much.
"That could take the pressure off my side, but we have to be up for the challenge."
Text at top (next game etc)
Next game: Darlington At Edgar Street On Saturday March 8th at 3.00pm