The tentative 12-team NFL playoff field heads into December with five teams that didn't qualify for last year's postseason.

Four of them — the 49ers, Packers, Vikings and Bills — make sense as bounce-back teams. San Francisco's Jimmy Garoppolo is healthy, Buffalo's Josh Allen is no longer a rookie, the Vikings are in Year 2 of the Kirk Cousins experiment, and Green Bay's Aaron Rodgers is still, well, Aaron Rodgers.

Then there's Pittsburgh. At 6-5, the Steelers hold the AFC's sixth seed long after everyone assumed it was over in Pittsburgh and that no Antonio Brown, no Le'Veon Bell and no Ben Roethlisberger would add up to Mike Tomlin's first losing campaign in 13 seasons as Steelers head coach.

Instead, Tomlin established a new identity on the other side of the ball as Pittsburgh has gone 6-3 since Roethlisberger suffered a season-ending elbow injury. A closing five-game stretch run starts with Sunday's rematch against the visiting Browns and could very well end with Tomlin's finest job of coaching in a career that's seen him win a Super Bowl at age 36 and reach a second one at 38.

"To me, he is the coach of the year," Brandon Marshall, a former NFL receiver, said two weeks ago as an analyst on Showtime's "Inside the NFL." "There are defining moments that bring a team together whether it's a game or a play or a situation. To see the job that he has been able to do in bringing them together has been tremendous."

Obviously, it's premature to say Tomlin is the coach of the year. But he is a dark horse candidate who will be hard to ignore if the Steelers return to the postseason while Roethlisberger sits, Bell misses the playoffs as a Jet, and Brown remains out of football as one of the most self-destructive superstars in NFL history.

A year ago, with Roethlisberger healthy, Brown catching a league-high 15 touchdown passes and James Conner making people forget Bell, the Steelers offense ranked fourth in yards (403.3) and seventh in points (26.8).

This year, with quarterback Mason Rudolph (5-3) starting eight games and undrafted rookie Devlin "Duck" Hodges (1-0) set to make his second career start Sunday, the Steelers rank 28th in yards (288.5) and 24th in points (19.6).

But the common thread that connects the Steelers, 49ers, Packers, Vikings and Bills is a leap forward in the rankings for turnover ratio. The 49ers and Steelers lead the way with both having jumped 25 spots from last year.

A year ago, the 49ers played 13 games without Garoppolo, won just four games and finished last in the league in turnover ratio at minus-25. They set an NFL record for fewest takeaways (seven).

This year, the 49ers are 10-1 while ranking seventh at plus-6. They already have 23 takeaways, fourth best in the league.

A year ago, the Steelers were 28th in turnover ratio at minus-11. They had only 15 takeaways while Roethlisberger's league-high 16 interceptions accounted for most of the 26 giveaways.

This year, the Steelers rank third at plus-10. Their 28 takeaways are second behind New England's 29. Their 14 fumble recoveries are tied for first with Seattle.

Twelve defenders have at least one takeaway. But it's the two new faces — first-round draft pick Devin Bush and in-season trade acquisition Minkah Fitzpatrick — who have taken the defense to another level. Bush has four fumble recoveries, two interceptions and a touchdown. Fitzpatrick has five interceptions, three fumble recoveries and two touchdowns.

"It is a collective effort," Tomlin told reporters recently. "They have collectively decided, and I am thankful for that."

The Steelers, Raiders, Titans and Colts all are 6-5 in the AFC. The Titans have the toughest strength of schedule remaining (36-20) followed by the Steelers (30-25-1), Colts (29-27) and Raiders (24-31).

Pittsburgh has three road games and faces two teams with a current winning record (Buffalo at home and the Ravens in Baltimore). If the Steelers can hang on and slip into the playoffs, it will be hard to dismiss Tomlin's case for coach of the year.

Mark Craig is an NFL and Vikings Insider. Twitter: @markcraigNFL E-mail: