Tony keen to see Packwood in action at Stadium:MK.
"He has over their 20 first team games under his belt and it was important he had some knowledge of first team football.
"We have watched him a few times and he is at the stage of his career where he needs to play some senior football.
"We had a couple of possibilities, and Will had been offered to us earlier in the season.
Tony said: "As soon as Magnus sustained the injury on Saturday, we were on the phones to sort out a replacement.
And the American could be in line for a debut at Stadium:MK this weekend.
Will was drafted in after Magnus Okuonghae was sidelined for an extended spell after rupturing his Achilles tendon in the game against Coventry last Saturday.
U's boss Tony Humes is looking forward to seeing loanee defender Will Packwood in action, after the centre half arrived from Birmingham City earlier this week.
The U's will make one of their shorter trips of the season at the weekend and will be backed in decent numbers from those making the journey.
"The fans have got behind us and been supportive of us since we came in as a managerial team," Tony added.
"At all of the away games, we've had good support and a good number there. They have been very vocal and it makes a difference and I'm sure it will be the same at Milton Keynes."
It promises to be a difficult test against the Dons, who have held something of a hoodoo over the U's in recent seasons.
But Tony is looking forward to the match, which promises to be an open game.
"The way they play is the same sort of way we want to play; an open expansive style and think it will be a decent game of football to go and watch.
"They have been a solid club in League One for a while now and we want to emulate them and get up the table on a more consistent basis.