ORCHARD PARK, N.Y. (AP) – Mike Mularkey grins when he recalls skimming the newly released NFL schedule last spring to see when Buffalo played Pittsburgh.

The Bills’ rookie coach never circled the date, but allowed himself one thought in considering what it would be like to face his former team for the first time.

“It’s funny, because you saw this game on the schedule and wondered what would be the implications,” the former offensive coordinator for the Steelers said Wednesday.

Mularkey can stop wondering.

Buffalo’s season finale at home on Sunday means everything for the Bills, whose playoff hopes hang in the balance.

Having overcome an 0-4 start, the Bills (9-6) have won six straight and nine of 11 to stay in contention for an AFC wild-card berth. To secure a spot in the postseason, Buffalo needs to beat Pittsburgh and hope either the New York Jets (10-5) or Denver (9-6) lose.

“I don’t know if you could write a script for the way it’s unfolding,” Mularkey said. “It’s interesting the way both teams have gotten to this point. It’s a good story.”

Mularkey plays down his role and shrugs off questions about his Pittsburgh past.

“It’s not about any of us. It never has been,” Mularkey said. “This is another opponent, another must-win game.”

The Bills have been playing must-win games ever since digging their early season hole, showing great resilience for a team accused of lacking mental toughness following last year’s 6-10 finish.

Buffalo is on its best run since winning eight straight in 1990 and have guaranteed its first winning season since 1999, the last time the Bills made the playoffs.

Buffalo also has an opportunity to match the 1992 Chargers, the only other team to reach the playoffs after an 0-4 start.

Mularkey deserves much of the credit for inspiring the turnaround.

He didn’t allow the Bills to unravel early, protecting his players from outside criticism by urging them to believe in themselves. And he tinkered with his lineup, elevating running back Willis McGahee to starter – a move that has coincided with Buffalo’s surge.

In fact, Mularkey has acted nothing like a rookie.

“Mike has never seemed like a guy who was doing this for the first time,” quarterback Drew Bledsoe said. “Nobody saw that train coming down the tracks that hit us the first month of the season. But to his credit, he stuck to his guns. … He’s done a tremendous job, no question.”

Not bad for a former NFL tight end who, following his retirement, spent a year selling computers before becoming Tampa Bay’s quality control coach in 1994. Mularkey then spent eight years with the Steelers, the last three as offensive coordinator before being hired by Buffalo in January.

Bills quarterback coach Sam Wyche was head coach for Tampa Bay when Mularkey got his first job. He’s impressed by how his former assistant has handled himself.

“The most important thing when you are going through that kind of period is the guy standing in front of the team needs to remain a pillar,” Wyche said. “He can’t be blowing in the wind, and he didn’t. … He kept our eye on the ball. He was like a veteran coach.”

The Steelers (14-1) present a big challenge, even though they have nothing to play for, having already secured first place in the AFC.

Mularkey knows Pittsburgh coach Bill Cowher too well to wonder whether the Steelers will take it easy on Buffalo.

Mularkey is aware of the game’s implications, but is sticking to the “one game at a time” approach he’s maintained since the beginning.

He added he’s been too busy working on the game plan to consider what it will be like to face the Steelers.

“There’s just not enough time to really put the emotional part into it,” Mularkey said. “Maybe as we get closer. But not right now.”