Because if they don’t? Ooh boy, now you’re looking at a mountain the size of Everest that has to be climbed without an oxygen mask in sight.

Seventh-ranked (Class 4A) Waverly-Shell Rock (2-0), which will invade Lynx Field to take on Webster City (1-1) in a non-district contest at 7 p.m. this evening, has averaged 8.1 yards per carry through two weeks of the regular season. That’s better than decent no doubt, but it’s not what causes hair on the back of the neck to stand up.

Meet McCrae Hagarty, a junior and one of the premier running backs in the class. A varsity contributor since his freshman season, the 6-foot, 205-pound bruiser enters tonight’s tussle averaging 17.1 — yes, 17.1! — yards per carry. He would no doubt have more than 16 attempts through two weeks had the Go-Hawks not shelled Waukon (45-6) and Crestwood (48-6) by a combined 81 points.

“It’s because he doesn’t get tackled,” WCHS head coach Bob Howard said after watching Hagarty on video. “He breaks tackles and then has long runs. He’s very big and physical.”

WCHS junior linebacker Skyler Scott (23) sacks Boone quarterback Kyle Sharp last Friday in Boone. The Lynx will make their second home appearance this evening against No. 7-ranked (Class 4A) Waverly-Shell Rock at 7 p.m. DFJ photo/Troy Banning

But Hagarty has plenty of help. Fellow junior Asa Newsom, a 3-star prospect with offers from Iowa, Nebraska, Missouri and Kansas State, collects 7.0 yards per tote. Cayle DeBoer, yet another junior, averages a first down on each of his 11 rushes, and quarterback Grant Halverson has completed 14 passes with four touchdowns and no interceptions.

It looks daunting for WCHS on paper and Howard acknowledges that this will be the Lynx toughest test to date.

“It’s definitely a big challenge and a good measuring stick to see if we’ve improved over the last two weeks,” Howard said. “Defensively, we can’t get blown off the ball and then you better wrap up and tackle. The eyes need to be in the right place, where they’re supposed to be.”

The Lynx played inspired defense in Week 2, as they limited Boone (0-2) to less than 100 yards of total offense. Linebackers Keegan Hisler and Skyler Scott took up permanent residence in the backfield, ends Jamin Stuhr and Kyzer Stanley had no trouble reaching the quarterback, middle linebacker Jaxon Cherry stayed in position to clean up almost everything that got past the line of scrimmage, and the secondary picked off three passes.

It certainly won’t be that easy this week against the Go-Hawks, but it was a definite step in the right direction after a Week 1 loss to Humboldt.

Slowing down the W-SR offense will be easiest if the Lynx can play keep away. To do that, the offense will need to continue to progress as it did in a 332-yard rushing performance against Boone.

“That would certainly be the best defense to not let them have it,” Howard said. “But that also means you have to make first downs. We’ve got to be consistent and not stop ourselves on drives.”

Wingback CJ Hisler has his own big-play capabilities with 71- and 60-yard touchdown runs a week ago. He’s averaging 11.2 yards per carry through two games.

Newsom, who is being recruited collegiately as an outside linebacker, will certainly have the Lynx backfield in his sights. But he won’t be the first standout linebacker WCHS has faced in recent years and the stingy Go-Hawk defense is a lot more than just one player.

“We’ve seen good players before like (Jacob) Imming from Sergeant Bluff-Luton,” Howard said. “(Newsom) is good, he’s very athletic and big, but they’ve got more than just him.”

TONIGHT

Waverly-SR (2-0) at Webster City (1-1)

Where: Lynx Field, Webster City.

Kickoff: 7 p.m.

Last Meeting: Webster City won, 28-21, on Oct. 11, 2013.

Notes: This will be the first meeting between the two programs in the last eight years … WCHS has won three of the previous five meetings … The Go-Hawks last win in the series was in 2012, 24-8 … W-SR is ranked No. 7 in Class 4A by the AP.