They've tried a reserve tight end with the right size, a backup linebacker with the right shape and a handful of running backs with (almost) the right speed.
They might all add up to Derrick Henry, but here is the problem for Michigan State: Not one is Derrick Henry.
The Spartans might as well be trying to prep for a unicorn ride or UFO landing.
"How do we prepare them to tackle Derrick Henry?" Michigan State co-defensive coordinator Mike Tressel asked with a chuckle. "We've never had a Heisman Trophy winner in the history of Michigan State, so how do we simulate that? The best backs in the NFL might not be quite as big or quite as fast."
Think that's an exaggeration?
Think again. Henry, Alabama's workhorse running back, is a brute at 6-foot-3 and 242 pounds.
He has three inches and 22 pounds on Michigan State's No. 2 tackler, linebacker Darien Harris, whom he'll face in the Cotton Bowl semifinal Thursday.
"He's able to do everything," Harris said, "break out in the open field, stiff-arm, pass protect, catch out of the backfield. You definitely can't hit him up high. (Defenders) bounce off."
Alabama quarterback Jake Coker put it like this: "He's the biggest dude out there and runs faster than everyone else. The guy's a freak."
But what truly separates Henry is that he's an ultra-marathoner amid players running a mile.
Henry rushed 32 times for 236 yards against Texas A&M. Two weeks later, he carried 38 times versus LSU for 210 yards. His final two stat lines defied modern football: 46-271 against Auburn and 44-189 versus Florida in the SEC title game.
"I can't imagine what his body must feel like after a game," Crimson Tide receiver Richard Mullaney said.
Henry is the strong, silent type. You have to lean in to hear him. He downplayed his durability Sunday, simply calling it "a mindset thing."
But he did allow that he once had this reaction upon learning his number of carries: "Sometimes you be like, 'Damn!' "
Henry topped Herschel Walker's single-season SEC record for rushing yards with 1,986 on 339 carries. Walker needed 385 carries to churn out 1,891 yards in 1981.
Alabama offensive coordinator Lane Kiffin said he's generally a proponent of backs carrying no more than 20 to 25 times because when they get tired, ball security is compromised.
"Derrick blows me away," he said. "I'll ask from upstairs (and hear): He's at 32, 36, 38 carries. We talk about taking him out. But you see the body language. There's no reason to."
Henry started just two games coming into this, his junior season. The plan was for senior Kenyan Drake to chip in, but Drake went down with cracked ribs, a broken arm and a concussion. Drake said he'll suit up in the Cotton Bowl, so perhaps Henry will tote the rock a mere 30-35 times.
"Hopefully I can take some of the load off him," Drake said. "But he could carry it 60 times (if the coaches would let him). We wouldn't necessarily want him to get that many carries, but if that's what it takes to win, we'll give it to him every time."
Michigan State can't rely on the Heisman curse for an assist. Five of the last six winners closed out their seasons with a victory.
One piece of recent history is on the Spartans' side _ they were the only team to keep Ohio State's Ezekiel Elliott under 100 yards. Sandwiched between a 181-yard day at Illinois and 214-yard effort at Michigan was a 33-yard smothering against Michigan State.
But as the Spartans know, Henry is a different beast.
"We weigh about the same amount," noted 250-pound defensive end Shilique Calhoun. "It will be great competition."
