Donovan McNabb and Jake Delhomme have been around long enough to know what they shouldn’t do. They did it Sunday, and their teams lost.

Mike Holmgren and Tim Ruskell combined to get to the Seahawks to the Super Bowl last season. But for lack of a backup quarterback, Seattle will have trouble getting back this season.

A Damon Huard, Charlie Batch or a Trent Dilfer would be nice. But not a Seneca Wallace.

Start with the Eagles and Panthers, who lost because very experienced QBs made rookie mistakes.

We’re not talking about McNabb’s two interceptions, returned by Ronde Barber for Tampa Bay TDs. Those things happen.

In McNabb’s case, it was clock management at the end of the half that cost the Eagles three points in a game they lost by one on Matt Bryant’s improbable 62-yard field goal. In Delhomme’s case, he forced a ball that was picked off with Carolina in range of at least a late game-tying field goal.

The Seahawks?

Wallace is not Huard, Batch or Dilfer, whom the Seahawks allowed to go to Cleveland after the 2004 season. Nor Gus Frerotte, another very experienced backup.

A case-by-case look after a Sunday that had enough bizarre events and upsets for an entire season:

McNabb

Two weeks ago the Eagles’ quarterback was the front-runner for MVP, an award that’s not given after a quarter-season. He won’t get any votes for his performance Sunday.

There were the two Barber interceptions, although McNabb, in his customary clutch way, was still able to rally Philadelphia from a 17-0 deficit in the third quarter to a 21-20 lead before Bryant’s very improbable 62-yarder on the final play.

McNabb’s biggest mistake, at the end of the first half with Tampa Bay leading 7-0, was more subtle. With 10 seconds left and no timeouts left, the Eagles reached the Tampa Bay 6 and McNabb spiked the ball.

Now there were 8 seconds, time for one shot at the end zone and then a chip-shot field goal by David Akers. Instead, McNabb managed to complete a pass to tight end L.J. Smith, who was tackled at the 2.

Clock runs out. Half over. 7-0 instead of 7-3.The Eagles sure could have used those 3 points later.

Rookie QBs occasionally make that mistake. Guys like McNabb? Throw it anywhere but to a receiver who will get tackled in bounds.

It turns out that was the fourth time in 19 games McNabb has done something like that.

“He saw something there that turned out not to be there,” coach Andy Reid said. “I want the ball in the end zone. It didn’t go in the end zone. That’s what happens. I’m banking that he learns from it and we move on and we’ll score in those situations or throw the ball away.”

Delhomme

With his Panthers trailing the Bengals 17-14 and just more than 5 minutes left, the Panthers got the ball at their own 19. Delhomme, with the help of a 15-yard face-mask call on Madieu Williams, moved Carolina briskly to the Cincinnati 10. Easy range for a chip-shot game-tying field goal by very reliable John Kasay.

On second down, Delhomme tried to force a pass to Keyshawn Johnson at the back of the end zone between two defenders. Kevin Kaesviharn intercepted.

For all intents and purposes, game over.

Delhomme has always been a gambler, and most of his gambles turn into wins. He’s one of the better clutch QBs in the NFL.

“You want to make a play in that situation, and I thought that was a play to be made, but obviously it wasn’t,” he said. “It’s real disappointing. Disappointing is an easy word, but the way you feel inside is a whole lot more than just one word.”

Backup QBs

Holmgren and Ruskell, the general manager of the Seahawks, went into this season hoping Matt Hasselbeck could stay healthy.

And maybe they had faith in Wallace. That’s not unusual around the NFL – Peyton Manning’s only backup in Indy is Jim Sorgi, the 27th QB who’s been on the roster since Manning joined the Colts in 1998. And Jared Lorenzen, who has never thrown an NFL pass, is the backup with the Giants for Peyton’s brother Eli, although the more experienced Tim Hasselbeck (Matt’s brother) is the third-stringer.

But it hurt the Seahawks on Sunday against Minnesota.

On the first series of the second half Sunday with the score 10-10, Hasselbeck hurt his knee. He was replaced by Wallace, who basically is a Pittsburgh-style “slash” – he was used at wide receiver a bit last season. But until Sunday, he had thrown just 25 passes in three-plus seasons with the Seahawks.

On Sunday, he threw two interceptions, one on his second pass. And the Seahawks basically unraveled and lost 31-13. No, Wallace didn’t miss any tackles on Chester Taylor’s 95-yard TD run, but he also wasn’t about to rally the Seahawks from the 14-point hole that created.

With Hasselbeck out for at least three games, Wallace will get his first NFL start on Sunday at Kansas City, where Huard will be on the other side of the line.

With Shaun Alexander still out with a foot injury, it takes away the two primary offensive weapons from the defending NFC champions.

Compare Wallace to Huard and Batch, who have had stints as starters – Huard with the Dolphins, Batch with the Lions. Or to Dilfer, now with the 49ers, who was the starter on Baltimore’s Super Bowl winner in 2000.

Batch led the Steelers to an opening-night win while Ben Roethlisberger was recovering from an appendectomy. On Sunday, he filled in when Roethlisberger was hurt in the third quarter in Pittsburgh’s 41-38 overtime loss in Atlanta. That wasn’t Batch’s fault – he threw for 195 yards and two touchdowns and acquitted himself as a veteran should.

Huard? He’s been extraordinary since taking over for the Chiefs when Trent Green went down in the opener. He has seven TD passes and just one interception and his passer rating is 96.7, fifth in the NFL, allowing the Chiefs (3-3) to remain competitive.

Meanwhile, the unbeaten Colts got a scare Sunday when Manning was smashed to the turf a couple of times, but bounced back. He’s started all 134 games in his career, but he’s 30 years old and aging can often mean injuries.

Yes, Peyton is durable. But at some point, a contending team needs insurance.

Where, by the way, is Gus Frerotte when you need him?

Answer: St. Louis. If Marc Bulger goes down, he’s a better alternative than Wallace if the Rams and Seahawks go down to the wire for the NFC West title.

AP-ES-10-23-06 1809EDT