Three things to watch when Ohio State hosts Iowa on Saturday

COLUMBUS, Ohio (WCMH) -- Seen by many fans as the final dress rehearsal before a top-10 showdown, Saturday's game against Iowa is simply the next Big Ten test for Ohio State.

No. 3 Ohio State plays Iowa at Ohio Stadium with kickoff set for 3:30 p.m. as it looks to improve to 5-0 heading a game the following week at No. 6 Oregon. Coach Ryan Day said the Hawkeyes will be a huge challenge.

"We gotta win this game. This is going to take everything we've got to win this game," Day said. "And we gotta put the best players in there to win the game. Period. That's it. That's the focus right now."

Here are three things to watch.

Going for it on fourth down

Ohio State knows it will be tested by a rested team coming off a bye week that features a defense known for limiting teams on the ground. Iowa has allowed less than 100 yards in each of its first four games and has yet to allow a rushing touchdown.

That should raise alarm bells for a Buckeyes team whose strength has been on the ground thanks to Quinshon Judkins and TreVeyon Henderson. The duo have combined for 666 yards and nine touchdowns, and each averages over 8 yards a carry.

And with the defense that is expected to be at the Shoe, they may be needed to deliver on fourth down. Last week against Michigan State, the Buckeyes were 3-for-4 in fourth down conversions, with two of those plays resulting in touchdowns. While they demonstrated that they have no fear going for it, offensive coordinator Chip Kelly knows that he has to make smart calls.

"There's an analytic aspect to it, but I don't think it's always analytics. I think you have to get the flow of the game," Kelly said. "You also have to factor in what does that do to our team if you don't get it."

Kelly compared it to a poker game. The players might be all in but that comes with a risk.

"If you only have a pair of twos, they may have a better hand than you. That's what the situation is," Kelly said. "It's easy to say, fourth down, you should go for it all the time. That's not necessarily the case."

Defense avoiding a slow start

It took until 1:47 of the second quarter for Ohio State to finally force a punt last week against Michigan State. That follows the first half against Marshall, when the Thundering Herd scored two touchdowns on the Buckeyes.

Defensive coordinator Jim Knowles is the first to shoulder the blame when his unit is off to a slow start.

"We've started slow the past couple of weeks, and I blame myself for that," Knowles said. "There are thousands of permutations of what could happen."

Part of the frustration comes down to what Knowles sees on film leading up to the game and how it differs from what actually unfolds, forcing him to make adjustments at halftime. To his credit, the defense has done particularly well in the second half. After allowing 186 yards in the first 30 minutes against the Spartans, the Buckeyes limited them to just 60. And through four games, Ohio State leads the country in fewest points allowed, averaging 6.8.

A special homecoming for Luke Lachey

Saturday's game will see many former Ohio State athletes return to campus to get inducted into the OSU Athletics Hall of Fame. The list includes running back Jeff Logan, quarterback/receiver Braxton Miller, men's basketball player Greg Oden and Olympic wrestling champion Kyle Snyder. Former athletic director Gene Smith will also be enshrined.

There will also be a special homecoming for a player from the opposing team. Iowa senior tight end Luke Lachey hails from Marble Cliff and graduated from Grandview Heights High School. And the two-time team captain will have plenty of fans at Ohio Stadium, including his dad, Jim, a former Buckeye himself and in his 28th season as a radio analyst on football broadcasts.