Ray Lewis isn't the only NFL star in his 30s whose career is at a crossroads -- and whose performance greatly affects his team.
Tom Brady and Peyton Manning have now reached their 30s, and as they go, so go the fates of their teams. Roughly 167 players age 30 and older -- an average of more than five per team -- are starters. These players either provide veteran leadership or are the focal points of their teams.
Here are the top 10 players in their 30s to watch this season:
1. Jake Delhomme, 33
He'll either be the Comeback Player of the Year or the Panthers won't be able to bounce back from mediocrity. John Fox is resting the season on Delhomme's tender right elbow, which underwent Tommy John surgery. The return of Delhomme -- whose backup is Matt Moore, an undrafted waiver claim rookie from last September -- could spark a playoff run. Before he was lost for the season, Delhomme had a 111.8 quarterback rating and the Panthers offense was scoring a playoff-worthy 25 points a game. Fox plans to take some of the pressure off him by running the ball more, but it's going to be Delhomme's job to win the close games.
2. Thomas Jones, turns 30 on Aug. 28
Jones might have been more valuable to the Bears' Super Bowl XLI run than Chicago wants to admit. His one-cut-and-go style fit the Bears' running attack better than Cedric Benson. Eric Mangini and the Jets staked the franchise's future on fixing the running game, hiring former Nebraska coach Bill Callahan to coordinate the running attack. Jones has put together three consecutive 1,110-plus-yard seasons, but his yardage totals and average have dropped each season. Like retired Jet Curtis Martin, Jones has to find the fountain of youth at 30
3. Terrell Owens, 34
T.O. has become more of a teammate in Dallas, but he's in a contract year. His three-year, $25 million deal expires at the end of the season but he's not threatening to hold out or be a problem. With Terry Glenn being a 50/50 bet to be a factor this season, Owens can't let his play drop because of age. He turns 35 in December but takes great care of his body and his mind seems right. Still, Tony Romo has one of the thinnest wide receiver groups in football behind Owens if Glenn isn't back. The team counts on T.O.'s 81 catches for 1,355 yards and 15 touchdowns.
4. Jamal Williams, 32
Teams such as the 49ers, Jets and Browns struggled turning over from a 4-3 defense to a 3-4 because they didn't have a dominating nose tackle. The Chargers had no trouble years ago when they switched to a 3-4; they had Williams, who often is unblockable against double-team blocks. Williams turned 32 this year and his knees are starting to wear down. Last year, he played 13 games and played 41 percent of the snaps. The key to any 3-4 is having the nose tackle occupy two blockers; Williams' health and his presence are pivotal to the San Diego's Super Bowl run
5. Charles Woodson, 31, and Al Harris, 33
The Packers defense calls for Woodson and Harris to match up in man-to-man situations throughout a game. Last season, Woodson fought off injuries to have another great season and Harris went to the Pro Bowl. But the wear and tear, injuries and the cold caught up with Harris in the NFC Championship game. Harris turns 34 in December; by the end of the season, Harris, Ronde Barber of the Bucs and Nick Harper of the Titans will be the only 34-year-old starting cornerbacks in the league. The Packers need to both stay and play young.
6. Walter Jones, 34
Jones has been considered the league's best left tackle for years. He's gone to eight Pro Bowls and had seven straight All-Pro seasons. Mike Holmgren is leaving the Seahawks after the season, but the coach is still counting on Jones to block an opponent's right defensive end with no help, like he did in his 20s. Shoulder problems have nagged Jones for the past couple of seasons but he still has an agile body and impeccable technique. The Seahawks placed Mike Wahle next to him at left guard with hopes of reviving the magic the offense had when Jones and Steve Hutchinson dominated the left side of the line.
7. Marty Booker, 31
The Bears went retro in a desperate move to fix their wide receiving corps. After losing their best young receiver, Bernard Berrian, to free agency, the Bears went back to their former No. 1 receiver. It comes at a curious time. Booker turns 32 on July 31. He'll have either Mark Bradley or Brandon Lloyd on the other side of the field. In 2001 and 2002, Booker had 100- and 97-catch seasons. He hasn't caught more than 55 passes in any season since then, and the Dolphins thought he was done as a starter. The Bears are hoping Booker can save their receiving corps.
8. Marvin Harrison, 35
The Colts are confident Harrison can bounce back from the knee problems that destroyed his 2007 season. Manning still depends on Harrison's precise routes and ability to separate from defenders, but the wide receiver's Hall of Fame career is at a crossroads. Years of pounding have taken a toll on his knee -- he had a bursa sack problem near the kneecap that kept inflaming. The plan is to have him rest through training camp and be ready for the regular season.
9. Jeff Garcia, 38
Garcia's mind and leadership got the Bucs back to the playoffs last season. Garcia ended up being the only player in the NFC South to get a trip to the Pro Bowl. But can he squeeze out another Pro Bowl season from his body? He's the oldest starting quarterback in the league by three years, topping Jon Kitna of the Lions. Garcia also isn't happy with his $3.5 million salary, but is not expected to hold out. If Garcia can't repeat his 2007 season, the Bucs could have a losing record. Their schedule is tougher this year, and the Saints and Panthers should be better.
10. Donovan McNabb, 31
Rumors swirled last season that the Eagles might consider trading McNabb in 2008 because they used their top pick in 2007 on a quarterback, Kevin Kolb. McNabb is also getting to the point at which he could be getting a new contract. He turns 32 in November, but he seems to have re-established himself in Philadelphia. He bounced back from a knee reconstruction and should have all of his throwing mechanics back in order. The Eagles tried to trade for a No. 1 receiver, but none were available. The Eagles are hoping McNabb can take them back atop the NFC East.
John Clayton, a member of the Pro Football Hall of Fame writers' wing, is a senior writer for ESPN.com.