Allen Park — Despite a tight-lipped coach and quarterback at the top of a closed-door organization, clues were abundant at Lions headquarters this week that Matthew Stafford’s back injury might be worse than it originally seemed.

Stafford was listed as questionable on the second straight injury report, was a limited practice participant all week, and then missed a planned media session Thursday because his treatment ran long.

There was also proof on the stat sheet: Stafford’s 101 passing yards in a 17-3 victory at Arizona last week were the second-lowest of his 138-game professional career, only topping a game in which he was knocked out in the first half.

But Stafford and head coach Matt Patricia insisted Friday that it was business as usual, implying the 10-year veteran would be out there playing Sunday in Buffalo for his 126th consecutive regular-season start.

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“Played with it last week, so plan on playing with it again,” Stafford said Friday. “We’re all battling through stuff at the moment, everybody on this team, everybody probably in the NFL, to tell you the truth. So I’m just going to be out there, doing the best I can to help the team win.”

Two road wins against sub-.500 teams and another in the home finale against struggling Minnesota — along with a heaping helping of help among nine teams fighting for two wild-card spots — still leaves the door open for a postseason spot.

Barely, though, as ESPN’s gives Detroit a 4-percent chance at the postseason while Football Outsiders calls it 2.2 percent.

Those slim chances likely rely on Stafford being available and effective.

Stafford injured his back Dec. 2 in a 30-16 loss to the Los Angeles Rams, but has played through it, and told reporters after the game that he was fine.

“I don’t know what his pain level is, but I would say he’s battling every single day,” Patricia said. “He’s a tough guy, he’s fighting through an injury just like a lot of the guys are. A lot of guys are beat up at this time of the year, it’s just kind of what it is and it’s just day-to-day from that standpoint.”

If Stafford plays, it will complete his journey of playing a road game against every other NFL franchise, although his only road game against Kansas City was in London in 2015.

Stafford’s numbers are usually gaudy, comfortably reaching 4,000 yards in each of the last seven seasons with 4,257 in a 2014 Pro Bowl season serving as that span’s low.

This year, he will need to pass for 271.0 yards per game over the final three — a number he’s hit five times this year and not in more than a month — to reach 4,000.

For success Sunday, Stafford will be going up against a stout defense with limited weapons at his disposal.

Running back Kerryon Johnson (knee) was ruled out Friday after missing practice all week as was wide receiver Bruce Ellington (hamstring), joining injured wide receiver Marvin Jones, tight end Michael Roberts and the traded Golden Tate as former Stafford options who won’t be available in western New York.

In addition, rookie Tyrell Crosby will likely be getting his first start at right tackle as Rick Wagner (concussion) is out, making the matchup against the league’s top-rated defense an even bigger challenge.

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Five-time Pro Bowl defensive tackle Kyle Williams, 35, a player Patricia coached against many times for New England in the AFC East, leads the Buffalo stampede up front.

“He really is controlling a lot of what they do on the front,” Patricia said. “They run some stunts and some games and some different pick packages up inside and he’s really kind of coordinating a lot of that, and probably a lot of it is based on the calls that he’s getting from the other side of the ball. 

“This guy is explosive, he’s strong, he’s really just got some sudden movement with that combined strength that he can just slap a guy and get by him and be into the backfield pretty quick.”

That could be bad news for Stafford’s back as the close likely nears in another season of bumps and bruises for a quarterback who keeps showing up.

“I don’t think anybody in the league right now is probably 100 percent, we played a lot of football,” Stafford said. “I’m doing what I can to help us win.

“That’s the bottom line, that’s my only goal.”

Matt Schoch is a freelance writer.