Column: NFL’s second half brings new questions

Remember back a couple of months, just before the start of the NFL season, that much of the talk was about rookies Johnny Manziel, Jadeveon Clowney and Michael Sam?

Now, Manziel’s holding a clipboard in Cleveland; Clowney has had injury problems and hasn’t made a big splash; and Sam, the league’s first openly gay player, is no longer on a roster.

As is the case every year, the NFL’s GPS is … recalculating …

Now that most teams have played eight games, here are 10 questions heading into the second half of the season:

Who has been the best coach so far?

Arizona’s Bruce Arians. It’s hard to believe this guy went almost his entire career without getting the chance to be a head coach in the NFL. Dating to last season, the Cardinals have won 13 of 16, and part of that without some of their best players — Carson Palmer, Darnell Dockett, Calais Campbell, Daryl Washington. Not only that, but they’re playing in the league’s toughest division. If Arians keeps this up, he’ll win his second coach-of-the-year award in three seasons.

Will Dallas’ DeMarco Murray break the single-season rushing record?

Murray has 1,054 yards through eight games, so an identical second half would give him three yards more than the 2,105 Eric Dickerson ran for in 1984. Half of the Cowboys’ remaining games are against teams with defenses ranked among the top nine in yards per carry: Arizona, Jacksonville and Philadelphia twice. That said, Murray ran for 115 yards at Seattle in Week 6, after the Seahawks hadn’t given up more than 38 yards to any back in the first four games. Still, with the Cowboys hurting at quarterback, teams will be gearing up to stop the run. Here’s betting that in the next eight games Murray fails to average the 131.6 yards per game necessary to break the record.

What’s another big NFL record within reach?

Kansas City’s Justin Houston has 10 sacks through seven games. That puts him on pace for 23, which would break Michael Strahan’s record of 22 1/2. Like Murray, Houston is in a contract year. Talk about timing.

Will Oakland win a game?

The 0-7 Raiders could wind up with a “ring” this season — a zero in the win column — joining the 2008 Lions as the only teams to finish 0-16. That’s hard to do, though, in a league with so much competitive balance and so many unpredictable outcomes. Even though Oakland has the league’s worst record at this point, it hasn’t always been the worst team. New England got a scare from the Raiders, and so did San Diego. Derek Carr has the makings of a good quarterback. Still, this team has a tough remaining schedule, with the best opportunities for a victory being Nov. 30 at St. Louis and Dec. 14 at home against Buffalo. By season’s end, the Raiders will have at least two wins.

Who is this year’s worst-to-first team?

In each of the last 11 seasons, at least one team has gone from the bottom of its division to the top in consecutive seasons. This year’s eligible candidates are Buffalo, Cleveland, Houston, Oakland, Washington, Minnesota, Tampa Bay and St. Louis. All those NFC teams are currently in last. Buffalo and Houston are in second in their respective divisions, but unlikely to overtake New England and Indianapolis. The team with the best chance is Cleveland in the tightly knotted AFC North, and the Browns are legit.

What’s the next big conquest for Peyton Manning?

Now that he’s broken Brett Favre’s record for career passing touchdowns, Manning’s next major milestone is Favre’s mark of 71,838 yards passing — that’s more than 40 miles, by the way. The Denver quarterback is at 67,098, so he needs 4,741 to claim the record. Of course, it’s winning that matters most to Manning, and, let’s face it, anything short of a Super Bowl victory this season will be a mile-high letdown.

Is there hope for San Diego?

Having lost two in a row, the Chargers are desperate to avoid their familiar predicament: having to dig out of a big hole at the end of the season. The best thing they have going for them is Philip Rivers, who’s cruising at a most-valuable-player clip with 20 touchdowns and five interceptions. Most ominous? Check out San Diego’s final five games: at Baltimore, New England, Denver, at San Francisco, at Kansas City.

What’s the division to watch in the second half?

The NFC West. The Cardinals, off to their best start since 1974, have a two-game lead over San Francisco and Seattle but are facing a tough stretch run that includes games against the Cowboys, Lions, 49ers and two against the Seahawks. Pete Carroll’s trying to right the ship in Seattle, but you know the Seahawks are going to put up a fight, especially at home. And with San Francisco poised to get a bunch of defensive standouts back — Aldon Smith, NaVorro Bowman and Glenn Dorsey — the 49ers figure to loom large in the playoff picture.

Who’s the comeback player of the year so far?

Philadelphia receiver Jeremy Maclin is in the mix, as are Houston running back Arian Foster and Dallas linebacker Rolando McClain. But coming on strongest is Rob Gronkowski, the surgically reconstructed New England tight end who’s fresh off a monster game against Chicago: nine catches for 149 yards and three touchdowns.

Which division leaders are in the most tenuous spots?

In the AFC, it’s Cincinnati, where the 4-2-1 Bengals have a wafer-thin lead in the North over Baltimore and suddenly surging Pittsburgh, both 5-3. Once a vogue Super Bowl pick, the Bengals are 1-2-1 in their last four games.

In the NFC, Detroit. The 6-2 Lions are loaded with talent, and this could be their year, but having Aaron Rodgers and the regrouped, 5-3 Green Bay Packers breathing down your neck would make anyone nervous. Detroit’s season finale is at Lambeau Field.