FOXBOROUGH – At long last, the Patriots have their sights squarely focused on Week 1.

The season opener with the Las Vegas Raiders is five days away.

Right on cue, there’s a speed bump. And a significant one.

Christian Gonzalez, arguably the team’s best player, once again did not practice on Monday.

He hasn’t practiced since suffering a hamstring injury July 28. Even if he manages to suit up Wednesday, can he turn it around that quickly to play in a game after five weeks on the shelf?

The bigger picture point is this: with a paper thin roster, the Patriots really can’t afford to lose any of their better players, especially at certain positions.

Along with corner, left tackle, linebacker, tight end, and last but by no means least quarterback, all fall under that heading.

Lose Will Campbell, and there really isn’t a suitable replacement as Drake Maye’s blindside protector. Same for defensive leader Robert Spillane at linebacker, Hunter Henry or Austin Hooper at tight end, and of course, Maye.

The Patriots may have improved from last year in a number of areas, and may have inspired some enhanced expectations, but injuries are the one thing that will pull the rug out from those and how they’ll ultimately fare.

So right off the bat, they have a possible nightmare scenario.

Alex Austin has played well in Gonzalez’ absence both in practice and the preseason games, but the Patriots aren’t likely to get the same impact as having their young star shut down the opposing team’s best receiver.

The point of signing Carlton Davis III to a lucrative free agent contract was pairing him with Gonzalez. They form arguably the best cornerback tandem in the league. And, having two formidable corners on the outside playing lockdown man coverage allows the Patriots to do so much more on defense.

It allows them to send more people at the quarterback with the goal of making his life miserable.

With Gonzo likely out of that equation for Sunday’s season opener against the Las Vegas Raiders, barring a miraculous turnaround, it somewhat limits what Mike Vrabel and defensive coordinator Terrell Williams can dial up with the defense.

Instead of man-to-man, the Patriots might be forced to play more zone, which involves more communication in the defensive backfield.

Vrabel said Monday he has been pleased with Austin and undrafted rookie DJ James, who have stepped up with the absence of Gonzalez, as well as Davis.

“We’d love to have Gonzo back, trust me, we would,” Vrabel said, “but I think the other guys have stepped up and tried to take advantage of the opportunity.”

Vrabel wouldn’t indicate whether Gonzalez had suffered a setback with the injury, given the length of time he’s been out. He stopped short of acknowledging that when asked Monday if that was the case.

“Well, it just hasn’t gone – again, he’s working hard,” Vrabel said, choosing his words carefully. “Whether it’s, say, one injury is going to be three to four weeks, one is going to be one to two, everyone heals differently, so just making sure that when players are back, they can do their job with confidence, they can protect themselves out on the field, and they can’t make it any worse.

“Those are some things I try to use for guidelines when players are ready to play and get back there.”

Hamstrings are tricky. They can linger. The last thing the Patriots want is to have Gonzalez come back, re-injure the leg because it’s not fully healed, and start the process all over.

Looking at Sunday’s game, the Raiders don’t exactly have an all-world receiving corps to worry about.

Jakobi Meyers, their top gun, presides over a room that also features, promising rookie Dont’e Thornton Jr., Tre Tucker and the newly-signed veteran Amari Cooper.

Meyers, who was a 1,000-yard receiver last year, is the star of that group, so it’s not exactly a murder’s row of wideouts. Week 2, however, has Miami’s Tyreek Hill, Jaylen Waddle, and Malik Washington going up against the secondary.

Gonzalez being out or back and less than 100 percent would have a significant impact in that game.

So the length of his absence, and what he’s like when he returns, will factor into wins and losses the first few weeks, and possibly beyond.

Vrabel said the Patriots will have a better idea about his return, once he returns to practice.

“I think what’s good for us and for Christian and the team is to try not to be frustrated,” Vrabel said. “Obviously, those things happen, and it’s how we respond to them. It’s how hard we work to get back, the communication, all the things that he’s doing.”

Ultimately, it’s not what you’re looking for heading into the season.