Ledgerwood, who has been battling injuries, didn't take a single snap at MLB on Monday and instead was backing up Alex Hoffman-Ellis at the WIL spot.
Paul Wulff said Kaufusi brings more speed to the linebacking corps.
"We think he gives us some size, and so far in our special teams he's been very physical and he's tackled well," said Wulff. "You give him a little bit of space to move (at MIK) and not have to go up against a 300 pounder. It allows us to use his athleticism better. We've struggled at the position and we'll give him an opportunity to go in there. We know he's played very physical, he's played tough when he's had his opportunities."
ALSO GETTING EXTRA REPS with the 1's was Darren Markle, who saw action both at the SAM and WIL positions.
With Kaufusi now moving back in the box, usual DT Justin Clayton saw some action running at DE in place of starters Travis Long and Kevin Kooyman.
"After 2-3-4 games we're starting to get a better feel of what they can or can't do and maybe what their strengths are," Wulff said on the defense. "Because of our depth, we're still kind of moving some guys to fit some holes. That's part of our growth right now and it's a good thing because we can put them in spots that can help us and utilize them more."
IN THE SECONDARY, senior strong safety Chima Nwachukwu sat out Monday's practice because of a sore hamstring. Deone Buchanon filled in as the starter, but usual CB Anthony Carpenter was there too.
Wulff said with the emergence of corners Damante Horton, Daniel Simmons, Nolan Washington, with Aire Justin being the fourth option, the Cougars can bring Carpenter back to the safety spot. This too increases the Cougars' speed.
"We recruited him as a safety in high school," Wulff said. "It's probably maybe where he's the most comfortable. It gives us a guy who can be pretty physical and run a 4.5 back there. It gives us more speed in the safety position and we need that."
Along with Bucannon, Tyree Toomer was the other starting safety on Monday.
"I believe the people that we have there (all defensive spots) can make the plays but it all comes down to execution," Toomer said. "Lately as a defense we haven't been executing when we need to, and the critical points in the game are where we lack execution. And that's where we give up the big runs, the big gains, and they (opponents) get touchdowns.
"The people that can execute will be on the field."