North End are six points ahead of Athletic in second so King is aware goal-difference could come into play.
With regular players Kelvin Hove, James Satherly, Steve Burney unavailable and Quinn Mailman sitting out a second week following a red card against Massey, several of the club's reserve players will get a chance at the top level.
Even a weakened Athletic should account for the winless Red Sox.
"But the reality is we still have to do the job," King said.
"Red Sox aren't exactly slouches in their own right. We need to stick to the game plan and do the job. We know we've got the players to do it."
King said motivation wasn't and issue.
"There's still plenty for us to play for and, if we finish second, that's great for us because it'll be a step up from last season.
"You always get the end of season blues, players are winding down or starting to think about other things and the weather doesn't help but it hasn't been too bad motivating the lads - especially on weekends."
In complete contrast, Versatile Wanganui City head into the weekend on the back of two wins and a draw but face the daunting prospect of an away game to unbeaten Palmerston North Marist who sealed the league title with a come-from-behind win against Athletic last Saturday.
Coach Kelvin Francis said it would be tough and they will be without regular striker Anthony Bell, while Jack Jonas will also miss the trip.
"Which makes us a little bit thin but I've got a team to take and we'll throw the kitchen sink at them and see what happens."
City have found their feet in recent weeks, picking up seven of nine available points in the past three games.
But it hasn't shifted them from second-to-bottom and that probably won't happen unless they get points against Marist and beat Red Sox next week.
Francis said he'll add a fifth player into the midfield to counter Marist's strength there and leave Max Davidson alone up front.
City gave Marist a good fight in May, going down 3-2 in Whanganui.
"We came back quite well at them then but their quality shone through and that's why they're the league winner," Francis said.
"They have the Central League playoff coming up so they'll be looking to get their systems right.
"We don't want to go an lay down and we're getting to go to Memorial Park which is a great place to play."
Meanwhile, Athletic Reserves take on Red Sox Manawatu Latinos at 12.30pm at Wembley.