Expect both the Marshfield Pirates and the Siuslaw Vikings to have a chip on their shoulders when they do battle Friday at Hans Petersen Field.

Kickoff in a Far West League football game fraught with playoff implications is 7 p.m.

"I'm sure they'll be very motivated to play," Siuslaw coach Tim Dodson said. "Their hackles will be up, and we'll have to be ready to rock and roll."

Three games remain in the regular season for both teams, but none more important than this Friday's.

Both teams started the season 4-0. Both were ranked in the 4A top 10 last week. And both suffered their first losses last week in hard-to-swallow fashion.

Marshfield had been averaging more than 50 points a game before losing to 3A Harrisburg in Coos Bay, 18-15, in a hastily scheduled game.

Meanwhile, the Siuslaw seniors lost perhaps their last, best chance for their first-ever win over North Bend, 33-27. The Bulldogs have now won the past four meetings between the two schools after the Vikings won five of the previous six.

Marshfield and Siuslaw know a loss would severely diminish any chance of hosting a state playoff game.

"If we don't beat Marshfield, we'll be so low ranked we'll always be the visiting team (in the playoffs)," Dodson said.

The Vikings slipped to No. 16 this week in the Oregon School Activities Association ratings, which are used to set playoff pairings. The Pirates fell to No. 13.

First-place North Bend, oddly enough, is No. 17.

Complicating the equation is the Friday's cancelation of a Marshfield-Douglas league game. Douglas and Glide elected not to play following Thursday's tragedy at Umpqua Community College, setting up the last-minute game between Marshfield and Harrisburg.

"Nothing will be decided for another couple of weeks anyway, because there's no reason to," Dodson said. "Let's decide it on the field."

The Vikings, with a 22-player roster, will be attempting another David vs. Goliath triumph against a Pirates team boasting an 83-player roster.

"They're really good, they're loaded all the way around," Dodson said of Marshfield, a school with twice the student enrollment. "They're a really talented team.

"Athletically they are better, physically they are better, everything about them is better. But they still have to play a good football game, and they know that."

Five games into the season, the Vikings still have the same major concern.

"Injuries are my biggest fear, this team in particular," Dodson said. The veteran coach believes his kids make up in toughness what they may lack in numbers, size and team speed.

"Our kids are taking on a great challenge, and they're not backing off," he said. "It's awesome."

The Vikings continue to show their toughness from Monday practice through Friday's game.

"You watch us, hitting on Monday, getting after it," Dodson said. "And the kids are smiling, having fun, the physicality of it.

"Our kids have been amazing, I mean absolutely amazing, they really have. It's been a very pleasant group to coach."

LOOKING PAST THE PIRATES

Despite the loss at North Bend, the Vikings are well positioned for a playoff run, if not a league title.

After Marshfield, the Vikings host Douglas (1-3 overall, 0-1 league) on Oct. 16 (homecoming/senior recognition night) and finish league play at struggling Brookings-Harbor (1-4, 0-2) on Oct. 23 in Brookings.

The league's other top contenders — North Bend (3-2, 2-0), South Umpqua (2-3, 1-1) and Marshfield — play each other in the final two weeks, seemingly tougher roads to a title and/or a playoff spot.

Perhaps the biggest obstacle for the Vikings is the underwhelming performance of their opponents, which impacts their OSAA ratings.

Only two of Siuslaw's 2015 regular-season opponents have winning records, Marshfield at 4-1 and North Bend at 3-2.

South Umpqua and Hidden Valley are 2-3, Douglas 1-3 and Brookings-Harbor 1-4.

Newport, which forfeited its game Friday, citing a lack of healthy players, and 3A school Pleasant Hill are both 0-5.

The OSAA ratings are based on a Rating Percentage Index (RPI) and the Colley Bias Free Rating Method.

MAKING THE PLAYOFFS

Siuslaw and Marshfield are among 40 schools in the state classified 4A, and 24 make the playoffs.

Teams qualifying are placed in three eight-school groups.

Group A includes automatic qualifiers for the first round of playoffs the weekend of Nov. 6-7. Those teams include the seven league champions and the top league runner-up, based on the rankings.

The 4A leagues include the Far West, Cowapa, Tri-Valley, Oregon West, Sky-Em, Skyline and Greater Oregon.

Sixteen schools will qualify for the play-in round the weekend of Oct. 30-31 as either Group B (host) or Group C (visitor). Each league is guaranteed a play-in home game, with those teams hosting the next eight best teams, based on the rankings.

Siuslaw finished the 2014 regular season as a Group C qualifier, going 3-0 in nonleague games and 2-3 in the Far West League. The Vikings shut out Marshfield, 14-0, in Coos Bay in the play-in game, then lost their first-round game to Mazama, 42-12, at Klamath Falls.

For answers to frequently asked questions about the OSAA ranking system, go to

http://www.osaa.org/help/rankings