With apologies to Jed Hoyer, Dan Kiermaier probably has been the busiest Chicago Cubs employee this offseason. While Hoyer mostly has been working in stealth mode on revamping the Cubs roster for the 2025 season, Kiermaier, the team’s head groundskeeper, has been getting Wrigley Field’s field ready for a couple of Northwestern football games. The ballpark and field looked to be in perfect shape Friday afternoon, and Wrigleyville is ready for a massive invasion of Ohio State fans for Saturday’s 11 a.m. kickoff. Belated thanks were in order to the Cubs for missing the postseason, allowing groundskeepers more time to get the field ready, and to Mother Nature for the mild fall weather that kept most of the ivy intact on the outfield walls for NU’s homecoming game. “We started removing the mound and some of the clay the second week of October,” Kiermaier said Friday during last-minute preparations. “And we wrapped up the project on Halloween, in terms of laying all the sod.” About 30,000 square feet of new sod has been installed on the playing field, which once again will run from east to west — or from the right-field bleachers to the third-base box seats. Those old enough to remember when the Bears played at Wrigley Field know the field ran north and south back in the day, leading to field-goal attempts and extra points flying over the left-field bleachers and onto Waveland Avenue. Saturday’s game will be Northwestern’s fourth at Wrigley since 2010 and its third since 2021. The Wildcats have yet to win one and enter Saturday as a 28½-point underdog to No. 2 Ohio State. The inaugural affair against Illinois in 2010 was marred by a late decision to go only one way on offense because the proximity of the end zone to the right-field wall was deemed unsafe. It was comical for fans to watch the ball moved to the other side of the field to start each possession but left the Cubs red-faced since they had hoped to make college football an annual affair at Wrigley. The Wrigley renovation of the 2010s fixed that issue by allowing the field to be extended over the home dugout. But last year’s Northwestern-Iowa game was made memorable when a giant chunk of turf near the west end zone came loose during a goal-line stand and led to multiple delays late in the game. Social media posts mocked the mess, a recurring theme for the Cubs in recent years. Grounds-crew workers fix torn grass near the west end zone in the fourth quarter of a Northwestern-Iowa game on Nov. 4, 2023, at Wrigley Field.(John J. Kim/Chicago Tribune) Kiermaier said the turf problem was related to the sand beneath the sod, and that the issue has been rectified. “In terms of the layout, it’s very similar to how we’ve done it before,” Kiermaier said. “Our approaches have been a little different each time, trying to learn from the things we’ve had to work through the last few years. But we feel really good about everything in terms of the set up this go-round.” The Cubs have added some purple LED lights to the rooftop standards to present a light show featuring Northwestern’s colors, one of the new touches for this year’s games. Northwestern Medicine Field at Martin Stadium, the Wildcats’ temporary home on the lakefront in Evanston, would have sufficed for the final two home games against Ohio State and Illinois — NU plays the Illini on Nov. 30 at Wrigley. It has been a critical success in its first year as the Wildcats prepare to build a new home on the old Ryan Field site. Photos: Northwestern wins opener at its temporary stadium on the lakefront in Evanston But the decision to play at Wrigley gives fans a different atmosphere and obviously will bring in more revenue, considering Martin Stadium’s capacity is a little more than 12,000. A sellout is expected, thanks to OSU’s hard-core fan base. Iowa fans took over Wrigley Field last year in what turned out to be a boring, punt-filled game the Hawkeyes won. Buckeyes fans are expected to do likewise Saturday, turning Wrigleyville into their version of High Street, the famous bar-hopping area in downtown Columbus, Ohio. Murphy’s Bleachers will open at 7:30 a.m. to accommodate early-arriving fans. A look at the Wrigley Field ivy before a Northwestern-Purdue game in November 2021. (Jose M. Osorio/ Chicago Tribune) The famous Wrigley Field ivy also will be on display, albeit past its peak in terms of colors. The deep reds and purples are gone, but enough of the golden yellow ivy remains to provide a look rarely seen in Chicago since the Bears left for Soldier Field in 1971. Cubs fans have seen the ivy turn on three occasions — in the postseasons of 2003, 2015 and 2016, when they played into late October. By mid-November, the outfield walls typically are bare, just as they are when the Cubs start the season in late March and April. “The ivy is normally gone, but with the warmer October and lack of frost, it has really held on for longer than usual,” Kiermaier said. “It’s got some really good fall color, so there’ll be some nice added scenery for (Saturday’s) game.” An NHL official facetiously asked the Cubs if they could keep the ivy intact for the Winter Classic game between the Blackhawks and St. Louis Blues on Dec. 31. No such luck. The Hawks-Blues game will be followed by two days of Big Ten hockey. The inaugural Frozen Confines event features a pair of men’s games on Jan. 3 — Ohio State-Michigan and Penn State-Notre Dame — and an Ohio State-Wisconsin women’s game and Wisconsin-Michigan State men’s game Jan. 4. That will conclude a busy offseason for Kiermaier and Wrigley Field. Hopefully by then, Hoyer can say the same.