SAN DIEGO -- A diaper bag is a serviceable item with benefits. So is the cup holder in a movie theater seat. So is the string from which your sunglasses dangle.
But a starting NFL quarterback playing against one of the league's elite teams and receiving no help from those wearing his colors? Not so much.
Can you go from 18-1 and Super Bowl runner-up to playoff observer? Definitely. A 3-1 start might have disguised how average New England is without Tom Brady, but the season's fifth game did the Patriots no such favor. They were exposed. They're not very good today.
It's not likely the team that stumbled its way around Qualcomm Stadium against the Chargers on Sunday night will be playing in January. The Patriots have become incredibly average overnight. This is one of the few times you truthfully can insist one player does make all the difference. Brady is that terrific. Matt Cassel isn't.
San Diego needed its 30-10 victory like nobody's business, needed to restore its image as a team capable of winning the game of Roman numerals Feb. 1 in Tampa, Fla., needed to combine all that talent by whipping someone.
The Chargers could have scored 40 with ease. They were that dominant.
But while it remains unknown if Norv Turner's team can maintain such an elevated level against an approaching schedule with several potential hazards, this is obvious:
New England misses the injured Brady like the PGA does Tiger Woods for interest. Cassel isn't built to win consistently at this level and has no chance of rallying his team from deficits to victories on a weekly basis.
Falling behind by 10 with Brady at quarterback was cause to possibly not cover the spread in victory; falling behind by 10 now is cause to accept defeat.
You don't go from not starting since high school to replacing one of the best quarterbacks in NFL history and not suffer some failure. Career backups own the tag for a reason, and Cassel has all the applicable traits.
That's not to say average quarterbacks can't succeed. Gus Frerotte is 3-1 as the starter in Minnesota; Kerry Collins has won all four of his starts with Tennessee. But they have also been supported by other phases. They haven't had to win games by themselves.
Cassel, like many, can't.
"The Chargers were better than the Patriots across the board," New England coach Bill Belichick said. "They played better. They coached better. I don't know what else to say."
He never says anything of note, still as cantankerous a curmudgeon as ever. But he knows how a season of incredible promise was lost when Brady's left knee crumbled under a direct hit on New England's 15th offensive snap in its opener. He knows the difference between greatness and this:
New England trailed 17-3 at intermission Sunday but opened the second half by driving from its 22 to a first-and-goal from the 1. Over the next four plays, Cassel threw one ball away, threw another into the ground several feet from his intended receiver and didn't see a wide-open Ben Watson on fourth-and-goal, instead trying to run for the score and being stopped for a 1-yard loss.
Brady sees Watson. He makes the play. That's the difference. It's an enormous one.
"Definitely a discouraging situation," said Cassel, who was 22 of 38 for 203 yards with an interception. "We have to do a better job of matching intensity early. Consider it what it is: We got outplayed. We're disappointed, but we'll move on and get better and continue to work hard."
He can't make plays with his feet. His inability to throw long has (but for a few plays this season) removed the dangerous threat that is Randy Moss, which has made defending the Patriots more pedestrian than problematic. The running game lacks consistency. The defense has all kinds of issues up front and in the back.
Serviceable can win at quarterback in the NFL when all the other parts around it work. It has absolutely no chance when they fall short. This is the unenviable position New England finds itself in today.
The hawkers/Chargers fans standing along Friars Road outside Qualcomm Stadium late Sunday afternoon held up T-shirts with this message: BRADY IS A LADY.
He might be out of sight, but he is never out of mind. No one expected Matt Cassel to replace Brady and not struggle.
But when the evidence is this apparent, it's difficult to imagine the Patriots doing anything differently than you come the playoffs.
Which is to say watching.
Ed Graney can be reached at 702-383-4618 or email@example.com.