Final act to 49ers-Hawks rivalry?

NFL owners met in Dallas on Wednesday and barely discussed expanding the playoffs from 12 teams to 14.

Those talks are set for the owners meeting in March, but there's no need to rush things. Not with all the drama the 2014 playoff race has produced. Week 15 opens without a single team qualified for the playoffs, although five of the 12 spots could be claimed this week.

The 2014 season has been extremely fun because of how tight things have been among playoff contenders. Six NFC teams have nine or more wins, which has happened only four times in NFL history; the last time was in the AFC in 2000. Eleven AFC teams have winning records, but many of the 7-6 teams may be on the outside looking in unless they manage to get to 10 wins.

So while playoff expansion is still on the NFL's agenda, this year's race could create a compelling argument for the NFL to eschew fixing what some feel isn't broken.

Here are the trends to watch heading into Week 15.

1. NFL's best rivalry could be winding down: Jim Harbaugh's likely departure from San Francisco at the end of the season could dilute what has been the league's top rivalry. The San Francisco-Seattle battles became classic largely because of coaches Pete Carroll and Harbaugh, whose rivalry dates back to the Pac-12 when Harbaugh was at Stanford and Carroll was at USC. It has only intensified in the pros. Harbaugh is 4-4 against Carroll in the NFL, including last year's NFC Championship Game that was won by the Seahawks en route to their Super Bowl championship. Without Harbaugh, 49ers-Seahawks becomes just a good, divisional battle minus the flash.

The thought of Harbaugh leaving has already had an impact. The 49ers are playing like an 8-8 squad instead of a team that advanced to three consecutive conference championship games. What was supposed to be a Thanksgiving night delight between NFC West powers turned out to be a better sleep-producer than the tryptophan in a turkey dinner as Seattle easily won 19-3. The 49ers enter the rematch as 10-point underdogs. A Seattle win would end any chance of the 49ers winning the division and put their playoff hopes on life support.

In addition to Harbaugh's potential exit, other interesting components to this rivalry may also dissipate after this season. The Michael Crabtree-Richard Sherman feud could end if the 49ers don't re-sign Crabtree in free agency. And it's not out of the question for aging vets Vernon Davis and Justin Smith to be done in San Francisco. There's no question this series has been great. Savor this week's contest since it may mark the dissolution of the NFL's best rivalry.

2. Few surprises in AFC: From the beginning of the season, all signs pointed to New England, Denver and Indianapolis clinching their respective division titles. That may come to fruition for the trio Sunday.

The Patriots are a vastly different team than the one that lost to Miami in Week 1, which doesn't bode well for the Dolphins in this week's rematch. In the opener, Tom Brady didn't have a healthy Rob Gronkowski, who played only 38 snaps, and Brady was just getting to know Brandon LaFell, who didn't catch a pass. Cornerback Brandon Browner was on the suspended list, and Bill Belichick was just beginning to figure out what he wanted to do on defense this season. Now, the Patriots are dominating and looking much like the Super Bowl contender many of us envisioned.

The Broncos hope to lock up the West title against the Chargers, having won five of their past six games against San Diego, including a 35-21 victory on Oct. 23. Peyton Manning's recent struggles (more on that later) could make this a closer game than expected.

Finally, the Colts will celebrate another South title with a home win vs. J.J. Watt and Houston. Colts fans should be optimistic about a postgame celebration. The franchise is 21-4 all-time against the Texans, and Colts coach Chuck Pagano has won four of his five matchups with Houston. Andrew Luck threw for 370 yards in the first meeting, a 33-28 win.

3. Can Dallas hide its defense on the road? Jason Garrett's formula this season has been to lean heavily on running back DeMarco Murray and have Tony Romo throw shorter, safer passes to eat up possession time and keep the defense off the field. Except for in the Thanksgiving Day loss to Philadelphia, the strategy has worked. Chip Kelly knows, of course, that the Cowboys' defense yields 5.92 yards per play. In the first meeting, the Eagles averaged 6.2 yards and ran 75 plays, resulting in 464 yards.

This game could come down to the opening coin toss. The Eagles won the toss on Thanksgiving Day and elected to have its offense go against the Cowboys' defense to open the game. The result was a Mark Sanchez-directed 80-yard touchdown drive. Romo countered with an 11-play drive that stalled and resulted in a punt. On the ensuing possession, the Eagles marched back with an 88-yard touchdown drive to open a 14-0 lead.

Advice to Garrett: If you win the toss, don't defer. Take the ball on offense and hide your defense -- or risk playing from behind. Dallas doesn't boast the talent Seattle has on defense, so Romo and Murray may ultimately be Dallas' best defense against Philly.

4. Age catching up to older QBs? Over the past two weeks, Peyton Manning, 38, has shown a little bit of his age. He didn't throw a touchdown pass and was limited to 173 yards against the Buffalo Bills on Sunday. The Kansas City Chiefs held Manning to 50 percent on completions and 179 passing yards. Manning has now gone three weeks without a 300-yard game. In his defense, Manning has faced three tough defenses (Miami, Kansas City and Buffalo).

Plus, John Fox has shifted the offense into more of a run-based attack, with a 54 to 46 percent run-to-pass ratio over the past three games. It also hasn't helped that tight end Julius Thomas has been injured.

Another quarterback to monitor is Drew Brees of the New Orleans Saints. His overall stats don't indicate any problems -- he has thrown for 3,983 yards and 28 touchdowns -- but his team's 5-8 record is alarming. Something is not clicking with the Saints' offense. Tight end Jimmy Graham has only three receptions the past two weeks, and Brees has had some struggles hitting his other targets consistently and has been susceptible to sacks and picks. He may find the elixir for what ails him in the Chicago Bears, who haven't stopped many quarterbacks this year.

5. More quarterback changes: The big news in Cleveland is the start of the Johnny Manziel era. Seeing Brian Hoyer play his fourth consecutive bad game, the change was merited. Hoyer had only one touchdown and eight interceptions in the four games leading to his benching.

Manziel is only the fifth rookie since 1991 to start a game for a team with a winning record this late in the season, with Washington's Kirk Cousins the most recent example in 2012. Manziel faces a Cincinnati Bengals defense that might have trouble stopping him since tackling machine Vontaze Burfict is out for the season. He could have instinctively handled some of Manziel's scrambling and read-option plays.

Speaking of Cousins, Redskins coach Jay Gruden may have to pick between the benched QB and another benched QB, Robert Griffin III, to start this week since starter Colt McCoy is banged up. While Griffin may start, he isn't the long-term answer in Gruden's eyes. Just another day in the chaotic world of the Redskins.