For six days a week, Michigan cornerback Jourdan Lewis keeps his emotions hidden beneath a soft-spoken surface. He’s quiet and calm and hard to excite, except on Tuesdays.

Wait, Tuesday?

“Yeah, he always gets fired up on Tuesday for some reason,” linebacker Desmond Morgan said. “I don’t know why. He’s always out there yelling on Tuesday. [Otherwise], he’s always had that laid-back mentality.”

Lewis agreed with his teammates, and said it was no accident that they notice him chirping a little louder on that particular day of the week. The junior has taken it upon himself to provide the energy for Michigan’s defense on Tuesdays this year because, he says, he thought that was the day it was hardest for them to get excited on their own.

“Tuesdays are the low energy days [for the team],” he said, monotonously on a Monday afternoon. “If people don’t bring it, guys are turning it down like, ‘It’s just a Tuesday.’ I try to bring that energy.”

There’s probably a yarn to be spun here about tireless practice habits early in the week leading to good things on Saturday for a player emerging as one of the country’s top cornerbacks this fall. But, the truth is that Lewis’ recent success is probably more about him learning to embrace the natural personality that persists from Wednesday through Monday.

A year ago, Lewis was developing as a technician in the Wolverines' secondary -- an unexpected bright spot during a dark season. He led the team in interceptions (2) and pass break-ups (6). He still struggled, though, with letting the bad plays go. Busted coverages and complete passes nibbled at his focus and corroded his confidence.

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He says as an upperclassmen, he’s added a tool that’s essential for all cornerbacks -- a short memory. So yes, he can list off each reception an opponent has had against him this season (it’s a short list), but they don’t bug him like they used to. He recalls the confusion that led to Oregon State’s passing touchdown on his half of the field, but shrugs off the suggestion that’s it been motivation for him since then.

“[I can] calm down and let the game come to me,” he said. “People are going to catch balls on you, but you can’t think of it too much. You’ve got to go on and play again.”

That mentality means that mistakes don’t multiply this fall. No. 13 Northwestern tested him last weekend by throwing his way 11 times last Saturday. And while the Wildcats did complete four passes in his general vicinity (more than he allowed in the first five games combined), Lewis spent most of the afternoon clinging to receiver Mike McHugh’s hip like a pair of yoga pants.

His coverage kept those completions to gains of minus-2 yards, nine yards, two yards and 12 yards -- the last on an out route against prevent coverage during the final drive of the game. If you count the distance Lewis sprinted for his first career touchdown after raking a ball free from McHugh’s arms late in the first half, that’s a net loss of 16 yards and six points that Northwestern suffered when throwing in his direction.

His teammates, embracing their inner-Jourdan, were unfazed by his performance.

“Best corner in the country,” said safety Jabrill Peppers. “But it’s expected from him. It’s not like, ‘Oh, good job Jourdan.’ We expect that from Jourdan.”

This week will bring the year’s stiffest test to date for Lewis and a secondary that has chewed up and spit out quarterbacks. During its five-game winning streak, Michigan’s defense has faced 11 different quarterbacks. Eight of them finished with a QBR (measure on a 100-point scale) of 12.2 or lower.

Michigan State quarterback Connor Cook ranks ninth nationally in QBR (82.4) so far this season. Lewis said Cook and a talented group of Spartan receivers will be the best passing offense he’s faced all season. As often seems to be the case in these in-state rivalry games, Lewis has a history with some of the Spartans that dates back to high school. He first crossed paths with star receiver Aaron Burbridge as a junior playing defensive back for Detroit’s Cass Tech.

“He blew us out,” Lewis said.

So maybe the short memory is still a work in progress, but Lewis’ new unflappable attitude makes it a pretty safe bet that this weekend won’t be a repeat of that matchup.