Boston — Josh McDaniels just might have the toughest job in the NFL this coming season.

The New England Patriots' offensive coordinator has to prepare someone to replace Tom Brady. He has to get him to a level where moving on from the GOAT doesn't seem like a disaster. And, he has to do so in the midst of a global health crisis that is likely to curtail most, if not all, early camps and organized team activities.

Piece of cake, right?

Let's just say after Bill Belichick, there might not be a more important coach on the staff than McDaniels, especially in this post-Brady era. The pressure on McDaniels to deliver is perhaps more than ever.

"It's going to be a challenge, there's no question about that," said former Super Bowl-winning coach Brian Billick, "especially when you consider: 'Do you have the quarterback that you need?' and 'How good is he?'

"When you move on from the GOAT, that's a lot. You don't just plug in the next guy whether it be in terms of expectation, or productivity, or the style which you've been playing."

Right now, it looks like Jarrett Stidham, a 2019 fourth-round draft pick, is the man. How good is he?

That's still to be determined.

Two years ago, the Patriots made McDaniels the highest-paid coordinator in football, giving him a 5-year deal worth roughly $4 million per season.

He will be worth every penny — and then some — if he can coach up Brady's successor and turn him into a star. But whether it's Stidham or another quarterback behind Curtain No. 2, McDaniels is going to have his hands full. And that doesn't even take into account how the coronavirus pandemic will affect the rest of his offense.

McDaniels may have to trim the Patriots' voluminous playbook to fit into the team's shortened prep time. Aside from Belichick, all eyes will be on him going forward.

Billick, an analyst for the NFL Network, pointed out that given the Patriots offense "morphs from week to week, and Tom orchestrated that with Josh," it's not an operation that can instantly move on with another quarterback. The Patriots change their offense to suit the defense they're up against each week. Billick didn't believe that was achievable with another quarterback so soon after Brady.

"I would imagine the biggest challenge is to create the identity under whoever the new quarterback is going to be," said Billick. "It will clearly be more defined than what we saw all those years under Tom Brady."

Billick also made note of the shared institutional knowledge that existed between Brady, McDaniels and Belichick. That knowledge allowed them to instantly pull out plays that were effective against a certain blitz or defensive scheme as far back as 15 years ago and use them on game day.

"You're not going to have that," said Billick. "Certainly, it'll evolve, but it'll look a little more traditional, and a little more identifiable with whoever the quarterback is."

Translation: it'll be simpler.

Since Brady's departure, one of the more popular debate topics has been whether the GOAT made Belichick, or vice versa. The debate crosses over to McDaniels, as well.

Did Brady turn McDaniels into one of the more highly regarded offensive coordinators in the league? Will he flop without him?

McDaniels' work with Brady's successor will say a lot.

During his Patriots run, McDaniels has been without Brady for two stretches. One was the 2008 season, which Brady missed after tearing his ACL in the opener. The other was the four-game stretch in 2016 when Brady served his Deflategate suspension to start the season.

In the first case, Matt Cassel was the next man up. The Pats didn't make the playoffs that year, but did go 11-5.

Cassel started slowly, then McDaniels was eventually able to tweak the offense to better suit his strengths. Toward the end of the year, the offense was really clicking. Granted, Cassel jumped in with largely the same cast that was part of a perfect regular season the previous year with Randy Moss and Wes Welker in the mix. But the work with McDaniels was still notable.

Then, eight years later, the Pats went 3-1 without Brady, as McDaniels coached up Jimmy Garoppolo and Jacoby Brissett, who both started during that stretch. In Garopplo's first NFL start, he went 24 of 33 for 264 yards with a touchdown in a 23-21 win in Arizona. He was on fire in his second game, throwing for three touchdowns against Miami, before a shoulder injury took him out of that game.

As for Brissett, McDaniels changed the offense around to get the best out of him to beat Houston, with more option runs. That's likely what he'd do for Stidham going forward. Brissett did lose to the Bills, but McDaniels put both quarterbacks in positions to succeed.

Between those stints, the offense McDaniels ran as the head coach in Denver wasn't all that special. Later, as the offensive coordinator of the 2011 St. Louis Rams, there wasn't much happening, either.

So is it fair to expect that level of success or more toward the Cassel/Garoppolo/Brissett level?

"He's had varying degrees of success," said Billick. "Not the same as he's had in New England. But the point is, he's had to do it before (without Brady). He'll adapt and do it again."

Because the team is now faced with the transition of life after Brady, many are already writing off the Patriots. Billick was amused with that take.

"You can go broke writing off the Patriots," Billick said with a laugh. "But that was always with the combination of Bill Belichick and Tom Brady. Now, the quarterbacks you're talking about, maybe they're the guys, maybe they can do it ... but that remains to be seen.

"Obviously, that advantage for 20 years, knowing that each year, you can begin with, at least, 'we got Tom Brady.' You don't have that now," Billick went on. "You don't have that stability. So, it's going to be a change. I don't know if I'd write them off, but I don't know if you can go into every season and say this is a playoff team, or an elite playoff team. I don't know if we can readily put them in that category."