Last Wednesday, New York Jets coach Rex Ryan was his usually optimistic self when he was peppered with questions about whether quarterback Geno Smith would play the entire game against the San Diego Chargers on Sunday and whether Ryan would be the one to make the decision if Smith had to be benched.

“I think he will finish the game,” Ryan said. “I think we will play well. I think Geno will play well. I think our whole team will play well.”

In the baseball parlance, Ryan often likes to invoke, he went 0-for-4 and whiffed, swinging from his heels, on 12 pitches.

Smith didn’t finish the game, and the Jets played anything but well in an embarrassing 31-0 loss to the Chargers. By every measure except margin of defeat, it was the worst loss of the Ryan era — one that dropped the Jets to 1-4 for the first time under Ryan and may have signified the beginning of the end of one of the longest head coaching tenures in Jets history.

The Jets, who were the first NFL team to be shut out this season, were outgained 439-151. The Jets didn’t reach San Diego territory until there was 7:35 left in the game, and they only got there via a penalty.

Smith was yanked at halftime after going 4-of-12 for 27 yards and one interception. Michael Vick technically did a bit better (8-of-19 for 47 yards) but had just one completion in his first five series.

The Jets recorded 11 first downs, six of which they earned on their final two drives. While the Jets were 1-of-12 on third downs, the Chargers were 12-of-18.

The Chargers held the ball for 38:54. The Jets did outdo the Chargers in something — collecting penalties, a “battle” the Jets won easily, 12-5.

“They always say, well, it’s never as bad as what you think, it’s never as good as what you think,” Ryan said during a conference call Monday afternoon. “Trust me. It wasn’t very good.”

The only impressive performance by the Jets came from Ryan in the post-game press conference, during which he repeatedly took all the blame for the loss.

“First of all, I apologize to our fans, those that are left,” Ryan said. “This is on one person. It’s certainly not a quarterback or anybody else. It’s on me. Clearly got outcoached. Thought we had a good plan going in and obviously that wasn’t the case.”

The falling-on-the-sword act is sure to impress owner Woody Johnson, who is easily swayed by Ryan’s verbosity. It also sounded like an assertive, give-me-one-more-chance plea directed at general manager John Idzik, who should probably be the one falling on his sword for putting together such a flawed roster.

But Idzik isn’t expected to emerge from hiding to offer non-answers until at least the Jets’ bye week in November. So Ryan’s best hope is to boldly take the slings and arrows for Idzik while trying to fix the Jets’ many issues in time to piece together a run in a mediocre AFC East.

While Ryan’s contract was extended following last season’s surprising 8-8 finish, is not guaranteed beyond 2015, so he is basically coaching on a year-to-year basis. Failing to even reach .500 — or come close — would almost surely lead Idzik to fire Ryan.

“I’m not used to getting my butt whipped,” Ryan said Sunday. “I’ve been beat before, but not like that. Complete beatdown. But again, I ain’t quitting. Shoot, we’re gonna find out what we’re made of.”

He may not like the answers — especially with the Jets hosting the Denver Broncos and visiting the New England Patriots over the next two weeks. Worse yet, the games take place in a span of four days.

“I just have to go back and do a better job and ask what am I asking my players to do?” Ryan said. “And somewhere, it’s not good enough right now, clearly not good enough. So that’s what we’re going to do.”

REPORT CARD VS. CHARGERS

PASSING OFFENSE: F — Good thing for the Jets there are no numeric grades assigned here. Otherwise, the passing game would probably get a zero — as in, the number of times the Jets got beyond the 50-yard-line in the first three-and-a-half quarters. Coach Rex Ryan made the right move in benching QB Geno Smith, who was leveled on the second snap of the game and never appeared to recover on his way to going was 4-of-12 for 27 yards and a Hail Mary interception during five pitiful first half possessions. But QB Michael Vick (8-of-19 for 47 yards) was even worse. Vick 2-of-11 for 13 yards on his first five series before going 6-of-7 on a final meaningless garbage time march inside the Chargers’ 40-yard-line. To be fair, there’s not much anyone could do with a wide receiving corps “led” Sunday by WR Jeremy Kerley (three catches for 24 yards) and TE Jace Amaro (three catches for 19 yards), but any hope the Jets had that a consistently misfiring Vick could save the season went out the window on Sunday.

RUSHING OFFENSE: F — The Titans are 1-4, same as the Jets, but they clearly knew what the Jets didn’t: Chris Johnson is done. Johnson (seven carries for 24 yards) ended any hopes the Jets had of a comeback when he fumbled on the play after CB Philip Adams picked off a pass in the end zone. Appropriately, the game ended with Johnson recording his only catch of the game for negative-two yards. RB Chris Ivory had nine carries for 44 yards, including three carries for eight yards before the Jets fell behind by two scores. Why, why, why a thousand times why aren’t the Jets using him more? RB Bilal Powell had two carries for six yards, which means coach Rex Ryan will probably gush again this week about how the Jets have three backs they love. Vick at least had two carries for 14 yards, but the second one was a rush of one yard that was credited to him after he threw a pass beyond the line of scrimmage. Of course.

PASS DEFENSE: F — The Chargers racked up “just” 288 passing yards, but it felt like at least twice as many. Every target of Chargers QB Philip Rivers got open at will, from ageless TE Antonio Gates (four catches for 60 yards and two touchdowns) to no. 1 receiver Keenan Allen (three catches for 25 yards) to slot receiver Eddie Royal (three catches for 40 yards) to deep threat Malcom Floyd (three catches for 72 yards). The Jets couldn’t even stop Rivers from eluding pressure and dumping off a pass to a wide-open RB Branden Oliver for a 53-yard gain. The biggest offenders were CB Darrin Walls, who got beat repeatedly on long routes, and safety Antonio Allen, who was no match for Gates. But it’s not Walls’ fault he’s a career-long backup pressed into starting duty or Allen’s fault he keeps getting jerked from cornerback to safety. Alas, GM John Idzik won’t emerge from hiding to give non-answers about this decrepit secondary until the bye week. The long bright spot was Walls, who made a leaping grab to pick off a Rivers pass intended for Allen in the end zone. Perhaps he can do that a lot next week against the high-octane Broncos?

RUSH DEFENSE: F — The sight of Oliver, an undrafted rookie free agent who began the season fourth on the Chargers’ depth chart, running through the Jets’ vaunted rush defense with zero resistance was the most alarming bit of evidence that the Jets are this close to packing it in. The Jets hadn’t allowed an opponent to reach 100 yards rushing all season, but Oliver racked up 114 yards on just 19 carries. The player Oliver replaced, RB Donald Brown, had consecutive runs of 13 yards and seven yards early in the second quarter and might have put up Oliver-type numbers if he wasn’t concussed later in the second.

SPECIAL TEAMS: C — Well, at least Ryan Quigley is cementing his grip on the punter job? Quigley averaged 51.1 yards per kick on eight punts. Kicker Nick Folk’s day consisted of booting the second half kickoff into the end zone for a touchback. WR Saalim Hakim’s job should be in jeopardy after he took five kickoffs out of the end zone and failed to reach the 20-yard-line three times (and only got to the 20-yard-line one other time). He was also flagged for unsportsmanlike conduct on a Chargers punt return. WR Walter Powell had two punt returns, one for seven yards and one for negative-two yards.

COACHING: F — The clock officially began ticking on Ryan Sunday — if not during the game, then after it, when LB Demario Davis told ESPNNewYork.com that the Jets are “not practicing like a championship football team.” Such a claim runs counter to the consistently sunny practice reports Ryan offers every Wednesday, Thursday and Friday. If Davis is right — and he’s not the type to mouth off — then it’s a strong indication the Jets are beginning to take advantage of Ryan’s player coach tendencies. As for the game, the Jets looked ill-prepared, poorly disciplined and borderline unmotivated on both sides of the ball. It’s easy to say the Jets’ defense tired from being on the field so much on a 90-degree day, but the Chargers began the afternoon with an 11-play, 90-yard drive. It was one of three 90-yard touchdown drives for San Diego. Offensive coordinator Marty Mornhinweg called a rush/pass ratio of 9:9 before the Chargers went up 21-0. He’s still criminally underutilizing Ivory.