Let's call in a playoff preliminary. There's too much football left to call No. 7 Stanford-No. 8 Notre Dame and No. 4 Ohio State-No. 9 Penn State a pair of College Football Playoff quarterfinals. Except it feels that way as four of the top nine teams in the nation meet with September coming to a close. Sure, it's early, but here's why each can't afford to lose …

  • Notre Dame because it doesn't have the luxury of a conference championship game. In the playoff era as in the BCS era, it's best to go undefeated. In fact, the Irish's only title shot in the last 30 years (2012) came after a 12-0 season. Lose and Notre Dame's best shot is to go 11-1, leaving it to compete for the playoff with 12-1 (and 13-0) conference champions.
  • Stanford because the Pac-12 tends to eat its own. Last year, each team in the league lost at least three games. The Cardinal still have trips left to Arizona State and No. 11 Washington. Utah is straight ahead next week.
  • Ohio State because of last year. The Buckeyes are the defending conference champions, but losing twice last year was the difference in the Big Ten missing the playoff. A win over the Nits allows the Buckeyes of the "luxury" of losing once in the conference and still having a playoff worthy 12-1 resume.
  • Penn State because it cannot blow this chance. If it loses, Ohio State would have to lose twice in the Big Ten just for Penn State to have a chance to win the division. Win and the Nittany Lions would have the inside track as the only undefeated team in the ultra-tough East. No. 21 Michigan State and No. 15 Wisconsin still have to come to State College. The only road games left are Indiana, Rutgers and No. 14 Michigan.

Let's take a look at the top storylines in college football as we enter Week 5.

1. Brian Kelly throws shade at Stanford: Notre Dame's coach must be feeling it. Kelly had some subtle hot lava on the "Jim Rome Show" for the Cardinal and their, uh, tradition. "They've had a really great run over the last 10 years," Kelly said. "We've had one over the last 90 years. There's a difference between longevity and championships."

Never mind that has absolutely nothing to do with the players on Saturday, it is true. The modern age of Stanford football basically begins with the arrival of Jim Harbaugh in 2007. Notre Dame is pretty much a college football founding member. But Stanford has won seven of the last nine meetings, all since 2009 when Harbaugh was establishing the Cardinal nationally.

2. Book it: This is a game of emerging quarterbacks. Notre Dame's Ian Book seems to be the arm that Kelly lacked with Brandon Wimbush. David Shaw hinted this week that Stanford QB K.J. Costello (327 passing yards against Oregon) could be great. "I believe there is a very high ceiling," Shaw said of the 6-foot-5 junior. "He's not where he's going to be four games from now." Shaw added that Costello's arm strength is "comparable" to one Andrew Luck.

3. Nick Bosa's injury: We know how that Ohio State's star defensive end is out until at least November. Not only is Bosa the Buckeyes' best defensive player, he might be the team's best player. It was after Bosa was flagged for targeting and tossed last year at Iowa, that the Bucks got run out of the building in the game that kept them out of the playoff. Coincidence? Consider that his replacement, freshman Chase Young, is the fourth-best pass rusher in the country this week, according to Sports Info Solutions. The five-star freshman is tied for fifth nationally in quarterback hurries.

4. Dear Trevor Lawrence, don't get hurt: The feeling here is that Clemson coach Dabo Swinney knew exactly how the Kelly Bryant situation was going play out. Either Bryant was going to stay and Clemson (hosting Syracuse) would have some of the deepest quarterback depth in the country, or without Bryant, Lawrence was going to have three shots at a national championship as a starter (assuming he lives for the NFL after the 2020 season). Even though now Lawrence is backed up by two freshman, he gives Clemson the best chance to beat Alabama -- now through 2020.

5. Meanwhile, Justin Fields is staying at Georgia: Surprised? It's worth mentioning that Georgia's prized freshman quarterback played all of one snap last week against Missouri. Fields might get some time this week against a Tennessee still trying to figure it out. This is one of the worst matchups of the week. Tennessee turned it over five times last week against Florida (leading to 31 points). Georgia has four non-offensive touchdowns in the last two games.

6. Texas is back … right? We won't know for sure until the Red River Showdown on Oct. 6. To get there, the No. 18 Longhorns have to win at Kansas State, a place they haven't won since 2002.

7. Road trip-plus for Mountaineers: West Virginia makes its longest Big 12 trip (almost 1,500 miles) to Texas Tech. The winner can do no worse than be in a tie for the Big 12 lead heading into October. Coming off its first win over a top 15 team in seven years (2011), the Red Raiders are in a familiar spot -- first nationally in passing yards and last in the Big 12 in total defense. Take QB Will Grier, who throws to three top 10 receivers (in yards) -- David Sills, Gary Jennings and Marcus Simms.

8. Cowbells aimed at Dan Mullen: For the first time since he was at Florida (the first time), Dan Mullen will be facing those famed/cursed cowbells at Mississippi State. "I've been hearing them for many a year now," he said this week. "I know the environment." How hard can it be? Mullen made sure "Rocky Top" was played all week in practice before ripping the Vols by 26.

9. Nick's next branch to fall: Being a part of Nick Saban's coaching tree has its disadvantages. If Louisiana-Lafayette loses at Alabama (Bama is a 49½-point favorite), Ragin' Cajuns coach Billy Napier would be the latest former Saban assistant coach attempting to beat their mentor. After knocking off Jimbo Fisher and A&M last week, Saban is now 13-0 against his former assistants. ULL has never beaten a ranked team on the road. Tua Tagovailoa remains the only Power Five starter yet to take an offensive snap in the fourth quarter.

10. Group of Five report: There are five unbeaten Group of Five teams heading into Week 5 -- UCF, South Florida, Cincinnati, North Texas and Buffalo. Because the Knights, Bulls and Bearcats all play each other in the American, the most unbeaten teams we can be assured of is three. There has never been more than one unbeaten Group of Five team at the end of the season in the playoff era (since 2014).

Quick kicks: Rutgers may have taken over the title as worst FBS program. In consecutive weeks, the Scarlet Knights have been outscored by Ohio State, Kansas (yikes!) and Buffalo (double yikes!) 149-30. Indiana comes to Piscataway this week … Ohio State (eighth) and Penn State (12th) are among the leaders in average yards per play … Syracuse (4-0) hasn't been 5-0 since 1987, when Dick MacPherson was the coach and Don McPherson was the star quarterback … Hard to believe Penn State is playing host to a top-10 matchup for the first time since 1999 … LSU (vs. Ole Miss) has two turnovers in the last 24 quarters. It is tied with Kansas with fewest turnovers this season (one) … Oklahoma's time of possession against Army last week (15:19) was its lowest since 1995. Sad that stat can't be tracked back further. Anybody got a Big Eight record book? … Bryce Love's 254 yards (95th in FBS) mark his worst three-game total since backing up Christian McCaffrey in 2016 … Pittsburgh (at UCF) faces the team with the nation's longest winning streak for the second time in six games … Texas has won as many consecutive games against ranked teams as Alabama (three each).