FLORHAM PARK -- This was the final play of the Jets' eighth training camp practice, an untimed down in a last-second situational drill just outside the goal line. The offense would either score, or the defense would win the day.

Quarterback Josh McCown took the shotgun snap, and floated a ball high for Austin Seferian-Jenkins near the back of the end zone. The big-bodied tight end high-pointed the ball with Demario Davis draped all over him, and held on despite a few last-second desperation swipes from the linebacker.

The referees signaled touchdown, and Seferian-Jenkins spiked the ball with such ferocity Rob Gronkowski would be proud.

"I like 1-on-1 plays," Seferian-Jenkins told NJ Advance Media. "I like myself against anybody 1-on-1."

You'd be hard-pressed to find a player more impressive than Seferian-Jenkins these first three weeks of camp. Armed with a renewed sense of determination, and a suddenly-chiseled 6-6, 265-pound frame, the fourth-year pro has dominated most who attempt to cover him.

On Monday, it was Davis. On Tuesday, Seferian-Jenkins beat two defenders for a red-zone touchdown, and made another long catch up the seam while covered by cornerback Morris Claiborne. He looks very much like a legitimate offensive weapon.

And boy could the Jets use one of those.

As part of general manager Mike Maccagnan's offseason roster purge, the Jets cut receivers Brandon Marshall and Eric Decker. This week, they lost top wideout Quincy Enunwa for the season with a neck injury. Charone Peake and Robby Anderson, two players who have struggled mightily throughout camp, are suddenly atop the depth chart. A less-than ideal situation.

If Seferian-Jenkins can continue his strong play into the regular season -- although he's suspended the first two games -- he could be the team's No. 1 option in the passing game. At least right now, though, that's not on his mind.

"I'm not worried about anything like that, or thinking anything like that," Seferian-Jenkins said. "We'll see who's the No. 1 guy. I have no problem being No. 20 as long as we win games ... I'm going to do my part. When I have my opportunities, I'm going to cash in on them."

To this point in his career, Seferian-Jenkins has been a bit of a disappointment. A second-round pick by the Bucs in 2014, he has just 55 career receptions in 25 career games. He's known more for his off-field troubles -- two DUIs and a damning video leak by TMZ-- than on-field success.

This offseason, Seferian-Jenkins knew he needed a change. So he sought help to get his personal life in order. Once he did, the rest started to take care of itself. He cut alcohol and fast food out of his diet completely, lost 33 pounds, and returned to One Jets Drive for organized team activities, seemingly, a new man. His head coach took notice.

"He lost a lot of weight, he re-shaped his body, dedicated (himself)," Bowles in early August. "Obviously all the things you heard, he made a dedication to himself, so that's a credit to him. He's come in lighter, quicker, leaner and he's moving a lot better."

For now, though, the only people to see this "new Austin," as Seferian-Jenkins calls himself, are those at the Atlantic Health Training Facility, a few reporters, and several fans who made random trips to practice. Most throughout the NFL still believe he's the disappointing second-round pick who didn't make it in Tampa Bay.

When the Jets open the preseason against the Titans this Saturday, Seferian-Jenkins will have a chance to show the world that's not the case anymore. Are the nerves starting to set in? Pressure to prove naysayers wrong?

Not exactly.

"I'm super chill," Seferian-Jenkins said. "I don't get nervous or any of that sh--. I'm just ready to play, man."

Connor Hughes may be reached at chughes@njadvancemedia.com. Follow him on Twitter @Connor_J_Hughes. Find NJ.com Jets on Facebook.