Will McDonald IV was a man on a mission over the offseason, and the mission is greatness.

McDonald hired a chef and one trainer for strength and one for agility and his breakout season has him third in the NFL in sacks (eight) behind Trey Hendrickson (11) and Dexter Lawrence (nine).

It allows Will McDonald IV to dream.

“My goal is at least 20,” he told The Post. “Definitely aiming for 20 or more to break that sack record.”

Mark Gastineau holds the Jets franchise record with 22. Michael Strahan and T. J. Watt share the NFL record with 22.5.

Even with Haason Reddick on the other side of the D-line now, few would consider McDonald’s lofty goal realistic with only eight games remaining. He’s not one of the few.

“They’re gonna stack up each week,” he said. “I’m not really too worried about it as long as we get the win, but those are gonna come.”

McDonald has enjoyed a breakout season following a rookie season (three sacks) with limited opportunities.

Asked if he had something to prove, he said, “Not much to prove myself, just to try to be great. That’s ultimately what I’m striving for, it’s to try to be great, not good. … I have full confidence in being 100 percent great.”

McDonald has bulked up from the high 230s to 245-248 pounds.

“I think regardless whether I’m small or big,” he said, “I’m gonna still do the same thing.”

His spin move is deadly.

“It’s just something I perfected,” he said. “I actually didn’t use it that much in college [Iowa State], but coming into the league, that’s just something that I perfected.”

It is easier for him now to convert speed to power.

“It’s easier for me to do a lot of things because now I could have tackles on their heels because I’m out there getting more opportunities to go against ’em,” McDonald said. “Just make ’em think, ‘Alright, is he gonna do this? Is he gonna do that?’ rather than just coming in one time, then getting one rep, then switching sides, blah blah, this and that. Now I can have people on their heels and I could play off of that.”

The Jets aren’t hesitant to line up McDonald on either side.

“It doesn’t even matter which side I’m on,” McDonald said. “I just want to always make sure that I keep tackles on their heels.”

Defensive line coach Aaron Whitecotton was asked about the biggest strides McDonald has made this season.

“How much time you got?” he said. “Obviously, No. 1 is his maturity and his professionalism. Not that he was unprofessional or he was never an issue-type of player last season. But just learning the game, stepping up his preparation off the field, and this was without any fanfare — he’s not a social media guy, look at me, look what I’m doing.”

Whitecotton mentions the chef and the trainers and adds: “He’s changed his body. He’s learning the game, he’s learning the scheme, he’s at a much higher level. In the Pittsburgh game, we weren’t totally on the same page on one of the third downs, in terms of the D-line, we were trying to get a game set up. And he realized what was going on, and he fixed it, and we were alright.”

McDonald’s target Sunday against the Cardinals is the elusive Kyler Murray.

“Rushing the passer is something you can’t teach,” D.J. Reed told The Post. “Some guys just have a knack, have that bendability, that explosiveness to just beat offensive linemen, and he has that, like his spin move, pretty unstoppable. He has more moves than that, but, like, that’s his bread and butter.”

There were criticisms of Jets GM Joe Douglas for drafting McDonald with the 15th pick of the 2023 draft with wide receiver Jaxon Smith-Njigba still on the board.

“Guys were saying like, ‘Oh, we should have drafted this this this,’ just fans and stuff. ‘Oh, we didn’t need a defensive end.’ But you see him leading the league in sacks, or up there. I’m happy for him,” Reed said.

McDonald also has two forced fumbles and a fumble recovery as he improves setting the edge.

“We felt like going through the draft process that he was a perfect fit for what we do,” Whitecotton said.

McDonald wears Gastineau’s old 99.

Just sayin.’