Tom Brady’s first regular-season game as a 40-year-old is one he’s trying hard to forget.

The Patriots quarterback didn’t have a Brady-like game by any stretch during the season opener, an embarrassing 42-27 loss to the Chiefs.

Completing just 44 percent of his passes, the fifth-lowest percentage of his long and illustrious career, just made the eyesore look even worse.

Which brings us to the lock of the week: That scenario will change in a big way come Sunday. Brady is going to light it up against the Saints at the Superdome in New Orleans.

Why?

Brady can’t call his team out and then fail to deliver. He’ll be primed to set the tone and send a message that he’s just fine, and so is the offense.

Second, the four-time Super Bowl MVP is facing the Saints, who had the worst defense against the pass last year and still looked the part Monday night against the Minnesota Vikings.

That surely won’t hurt the cause.

Saints defenders made Vikings quarterback Sam Bradford look like a Hall of Famer. Bradford was 27 of 32 for 346 yards with three touchdowns and a near-perfect 143.0 rating in a 29-19 Vikings victory.

Let’s just say if Brady has as much trouble Sunday connecting with receivers as he did in the opener – he missed a wide-open Dwayne Allen up the sideline on New England’s first play and overthrew Rob Gronkowski on a seam route – the age question is going to start to surface.

Sure, give Bradford credit for a terrific performance, but let’s also remember the Saints surrendered 4,380 yards in the air for a reason last season.

Brady indicated he would be watching the game intently and was going to be taking notes. Well, he and Patriots offensive coordinator Josh McDaniels had to be licking their chops watching that secondary try to hold off Bradford and his little-known arsenal. Wide receivers Stefon Diggs (seven catches, 93 yards, two touchdowns) and Adam Thielen (nine catches, 157 yards) did most of the damage. Saints cornerbacks Marshon Lattimore, P.J. Williams and De’Vante Harris were no match. It’s hard to believe they’ll be any better against former Saints wideout Brandin Cooks, Chris Hogan, Danny Amendola (if he plays) and tight end Gronkowski.

Those defensive backs aren’t even in the same league as the Chiefs defenders. Brady is sure to pick them apart with whatever game plan McDaniels cooks up this week.

One bad game out of the chute, that can happen, especially when your best weapon, receiver Julian Edelman, is hurt and you’re adjusting to that loss. It’s in the realm, especially against a good defense.

Now, if the trend continues against a woeful pass defense like the Saints? Well, that’s another story. Then it’s time to sit back and take a closer look. If Brady continues to look out of sorts, especially during crunch time in the fourth quarter, maybe Father Time finally is creeping in to claim another soul.

If Brady goes back-to-back with bad games, the Jimmy Garoppolo talk is going to stir up. That’s pretty much a guarantee.

Against the Chiefs, Brady struggled on first down, going 5 of 15 with two sacks. He forced some throws into tight coverage and ultimately was forced to throw deep or out on the perimeter because Kansas City took away the short crossing routes that are his staple, packing the middle of the field in the second half.

Some of it was on Brady, some of it was on the play-calling, but most of it was on the Chiefs, who took away his best options.

It’s just hard to imagine Brady throwing up a stinker in Week 1, questioning the team’s effort then not following up with an amazing performance of his own the following week, especially against a pass-challenged defense.

“We just have to be a lot better in a lot of areas, starting with our attitude and our competitiveness,” Brady said after the loss to the Chiefs.

And he hit those same notes during his weekly radio appearance on WEEI.

“It’s execution, it’s attitude, it’s competitiveness, it’s urgency. It’s everything,” Brady reiterated Monday. “We’ve just got to do a better job. We played against a good football team, and we just didn’t get the job done.”

The stars definitely are aligned for Brady to follow with a great game. He should get the job done.

Hard to believe Brady will look washed up against the Saints team Bradford torched Monday night.