Michigan State got one offensive lineman back Saturday just as another went out.
Allen found out he would be starting during the week when Jackson went down.
"It felt good and I felt like everyone on the O-line really meshed today and we were ready to go," Allen said.
Allen confirmed he missed the first two games with turf toe, which occurred when he went to block a linebacker and when he got up, couldn't really walk.
He said the pain has subsided and doesn't hinder him now.
"It's not too bad. Take a couple Advil and I'm good," Allen said.
Jackson is expected to return and play for the Spartans in South Bend next weekend against Notre Dame.
Lewis expected back next week
"He got hurt in practice, but he'll be back and ready to roll next week," Narduzzi said.
Sophomore R.J. Williamon started in Lewis' place and made it an easy choice to hold Lewis out, Narduzzi said.
"R.J. might as well be a starter," Narduzzi said. "That's why we told Isaiah (Lewis) to take it easy. R.J. is a great player and we have a lot of confidence in him and you can pretty much say he's a co-starter back there."
Narduzzi not worried about Jones
Junior linebacker Taiwan Jones left Saturday's game with an injury and did not return, but Narduzzi said he isn't really worried about Jones.
"(Head trainer) Sally (Nogle) said he will be fine," Narduzzi said.