When Jack Allen first started taking reps at the tackle position this summer, it was a way to fool around, to earn some bragging rights by squaring off 1-on-1 with defensive end and friend Shilique Calhoun in drills.

When Allen -- Michigan State’s 6-foot-1 senior captain, largely considered one of the top centers in college football this season -- took snaps at left tackle during the second half of last Saturday’s 24-21 win against Purdue, it was the first time he’s played there against someone other than this own teammates.

"In a game? Never," Allen said when he last lined up on the edge of the offensive line. Through college, high school and even youth football, "I played center."

This is the state of No. 4 Michigan State’s offensive line as it approaches the meat of the Big Ten season. The group expected to clear the way for a potential playoff appearance this fall has been hit harder by injuries than any other unit in East Lansing, perhaps any unit anywhere, and is reaching for unorthodox solutions to keep moving forward.

Both starting tackles, juniors Jack Conklin and Kodi Kieler, missed last week’s game with leg injuries. Redshirt freshman Dennis Finley started in Conklin’s place, but broke his leg in two places in the second quarter. Running low on healthy bodies, the Spartans pushed Allen to tackle and re-arranged most of their interior linemen to fill his spot. No lineman who started the team’s first game of the season finished the Purdue game at the same position.

Conklin and Kieler practiced Tuesday, according to offensive line coach Mark Staten, but might not be healthy enough to play Saturday when Michigan State visits Rutgers. That leaves the coaching staff with a brain-teaser of mix-and-match options to solve by Friday night.

"There are probably six to 10 different lineups that I could put out there Saturday depending on if this guy’s healthy or that guy’s healthy," Staten said. " ... I’ve got a lot of fruit in my basket."

Staten’s cornucopia comes from the versatility he and the rest of the Michigan State staff have been working to develop in their linemen for the past couple years. Head coach Mark Dantonio said that group subscribes to the "whole-part-whole" theory of knowing everyone else’s job around you.

Allen has worked at several spots on the line this fall. So has his brother, Brian Allen, who started the season at guard, shifted to center last week and could potentially play right tackle if needed. Senior Donovan Clark, slotted as a potential starter at either spot on the right side of the line on this week’s depth chart, has played three different positions in his time at Michigan State.

"They all need to know what the other guy is doing," Dantonio said. "Many of the techniques are similar, to some extent. Guys have had opportunities. ... We have quite a bit of diversity, I guess, and age and experience with our senior group. So I think that gives us an advantage."

The diversity gives Michigan State the option to see which of its inexperienced linemen they trust the most and then shift their veterans to create an open spot at his position. There’s been more experimenting than usual in practice this week, but Staten said they have rotated through different lineups throughout the first two months of practice. He said he’s focused less on individual performances and more on how certain combinations of players work together.

"That’s the biggest thing," he said. "Who’s double-teaming well together? We’re going to run power. Who is working off each other in our zone game? Who is working off the one or the solo or the backside wedge? We’re trying to figure that all out."

The patchwork unit has held its own through five games. Michigan State’s offense has allowed only three sacks and is averaging 183 rushing yards per game. Experienced and athletic players like Allen have helped the Spartans avoid disaster while they wait for their starters to get healthy.