4 Iowa football matchups to watch as the Hawkeyes host No. 4 ranked Michigan on Saturday

Iowa football safety Kaevon Merriweather was reminded of a humbling fact shortly after the team's 27-10 win over Rutgers last Saturday.

The next opponent on the Hawkeyes' schedule is No. 4 ranked Michigan, who handed them a 42-3 loss in last year's Big Ten championship. If you recall, that blowout included a 21-point scoring frenzy in the fourth quarter. 

Ten months later, the Wolverines are traveling to Iowa City for a rematch. 

"Thirty-nine points, it's on my mind definitely," Merriweather said of the margin of defeat last season. "I think we're all ready and will be prepared for next week." 

The Hawkeyes will need their sharpest performance of the season and then some to secure a top-five win for the second season in a row. Michigan's had one of the most electric starts to the college football season, largely powered by its offense that's second nationally in scoring offense (50 points per game). 

And five-star quarterback J.J. McCarthy looks like the best quarterback that Jim Harbaugh has had in his time in Ann Arbor. 

More:Iowa football postgame mailbag: Where do Hawkeyes stand ahead of showdown with Michigan?

However, it's worth noting that Michigan will be tested on Saturday too.

Its first three opponents — Colorado State, Hawaii and UCONN — are three of the worst teams in college football according to the ESPN Football Power Index, ranking 125th, 129th and 128th out of a possible 131 teams. Michigan defeated Maryland, ranked 24th in the index, by a close 34-27 margin last Saturday but the Iowa game will bring new challenges.

It's Michigan's first road game of the season and by far the best defense they've played against.

Michigan might also be shorthanded: there's injury concerns with two of its better offensive players in tight end Erick All and running back Donovan Edwards. Both missed the Maryland game and are uncertain for this weekend. 

Saturday's contest is the marquee matchup (to date) for both teams. FOX's Big Noon Kickoff will be in attendance and the Hawkeyes will draw on a raucous Kinnick crowd for momentum throughout the game … kind of like last year's matchup against No. 4 Penn State when they came in early October. 

Here's four matchups to watch on Saturday: 

Michigan's rush offense is dangerous but thin at the moment 

McCarthy, the sensational sophomore, has gotten the majority of the headlines during Michigan's strong offensive start, but stopping junior running back Blake Corum is Iowa's top priority on Saturday. Corum powered Michigan to its win over Maryland carrying the ball a career-high 30 times for a career-best 243 yards and two touchdowns. 

Through four games, Corum ranks fifth nationally in yards per carry (7.5) but perhaps an even more impressive statistic is that overall, Michigan running backs average nearly three yards per carry before contact. And that's because the offensive line's elite play. 

The unit won the Joe Moore Award for the nation's best line last season and is nearly as formidable this season. They returned three starters officially at left tackle and both guard spots, starting right tackle Trente Jones was the swing lineman last year and the Wolverines added transfer Olu Oluwatimi from Virginia, who was a Rimington finalist last season for the nation's best center. 

More:Leistikow's 6 thoughts from Iowa's impressive 27-10 win at Rutgers

Iowa's one of the best tackling teams in the country at all three levels; that will play a huge factor in Saturday's game. On average Corum breaks 7.6 tackles per 20 attempts, fourth best in the nation. 

However, there's concern with the depth behind Corum. His usual running mate, Edwards, has missed the last two games and is uncertain for Saturday. The third string running back is true freshman CJ Stokes, who fumbled in his only attempt of the game against Maryland. If Edwards can't go, it will likely be another 25-plus carry day for Corum. 

Examining Iowa's pass offense vs. Michigan's secondary 

A growing theme for Iowa's offense over the last few weeks has been more passing attempts down the field. The Hawkeyes took several deep shots against Nevada in Week 3 and converted on a few long passes against Rutgers, including a 42-yarder to tight end Sam LaPorta on their longest scoring drive of the season (87 yards that resulted in a field goal). 

This Saturday's game will feature two of the best defensive back units in the country. Where you see Michigan ranked fourth nationally in pass yards allowed per game (135.8), second in yards per attempt (4.68) and fifth in yards per completion (9.20), Iowa's unit is either just behind or just ahead. Simply put: Iowa's struggling pass offense, ranked 124h nationally in passing yards per game, will have its hands full. 

Cornerback DJ Turner, an All-Big Ten honoree, is the leader of the unit and the emergence of fellow senior Gemon Green has created a formidable combination. Green was benched during the 2021 season after a rough 2020 campaign as a starter. He's turned it around this year, prior to Maryland he hadn't allowed a catch this season. 

More:Podcast: What does Iowa football's win at Rutgers tell us about the Hawkeyes' Big Ten road ahead?

The challenges of Michigan's talent in the backend is compounded by injury concerns for Iowa. Sophomore Keagan Johnson's health is a lingering question mark, and there's a new injury to monitor — fellow sophomore Alrand Bruce IV, who was almost a late scratch against Rutgers according to coach Kirk Ferentz. 

"We weren't sure if AB was going to be able to answer the bell (last Saturday)," Ferentz said via radio after the game. "We wanted to take (punt returns) off him, at least. Fortunately, Arland was able to play."

Those injuries will be worth monitoring throughout the week. Passing yards will likely be hard to come by, which means Iowa's rushing offense will need to take another step forward. Comparatively, Michigan's rush defense is ranked 35th nationally allowing 109 yards per game. 

How does Iowa's defense match up with J.J. McCarthy?

The last time Iowa played Michigan, it wasn't McCarthy as the full-time starter but senior Cade McNamara. A quarterback competition persisted in Ann Arbor through the off-season and into the first two games of this season but it became undeniable that McCarthy is the superior option. 

The dynamic former five-star recruit has dazzled in his first few games as a starter. On the year, he's completing 80% of his passes with five touchdowns and zero interceptions. And unlike McNamara he's a considerable threat on the ground, averaging 6.5 yards per attempt with one rushing touchdown.

More:FOX's Big Noon Kickoff Show coming back to Iowa City for Hawkeyes' game vs. No. 4 Michigan

But the biggest difference with McCarthy under center is the big-play ability in Michigan's pass offense. McCarthy leads the nation in yards per attempt with a whopping 11.6 yard metric, compare that to McNamara who holds a career average of 7.5 yards per attempt. And Michigan's top three wide receivers: Ronnie Bell, Roman Wilson and Cornelius Johnson are all averaging at least 15 yards per catch. 

But his last game against Maryland revealed a truth: his eccentric play is part of the reason why he's so dynamic but it also opens the door for possible turnovers. 

Officially, McCarthy had zero turnovers against Maryland but he received lucky breaks. He fumbled twice, one on a designed quarterback run and another while scrambling aimlessly in the backfield instead of throwing the ball away. Both times the offense recovered. He also almost had a costly fourth quarter interception by forcing the ball to Bell near the goal line. 

Iowa's one of the most opportunistic defenses in the country. The chess match between the Hawkeye defense, sticklers for not allowing big gains and Michigan's dynamic offense might be the matchup of the day.

Can Iowa limit explosive plays and even steal a few possessions for its offense? 

Another big test for Iowa's offensive line 

Even more than quarterback play and wide receiver health, Iowa's shaky offensive line play might be the team's biggest question mark. They built momentum against Rutgers, largely dominating the matchup but the biggest challenge of the season is ahead on Saturday. 

More:Iowa's offense took a positive step in win over Rutgers. Here's what we saw from the Hawkeyes.

The 2021 Big Ten championship game was a complete mismatch as the Wolverines had two NFL first round talents at defensive end, Aidan Hutchinson and David Ojabo.

As for this year's Michigan front four, the jury is still out. 

Michigan recorded 33 pressures and seven sacks in its Week 1 win over Colorado State but only had one sack combined against Hawaii and UCONN. The front four had trouble getting pressure against Maryland as well, prompting a lot of blitzing by defensive coordinator Jesse Minter. All three sacks came from linebackers or defensive backs. 

Whether it's halting the initial rush or soundly communicating on blitz pickup, Iowa's offensive line will have to take another step forward for any chance of points on Saturday. The name to watch for Michigan is nose tackle Mazi Smith, an athletic wonder who had a career-high eight tackles last week. The biggest concern on Iowa's line is the interior, limiting his impact on the game will be crucial to success. 

Kennington Lloyd Smith III covers Iowa Hawkeyes football and men's basketball for the Des Moines Register. You can connect with Kennington on Twitter @SkinnyKenny_ or email him at ksmith@gannett.com.