FLORHAM PARK, N.J. — Kenbrell Thompkins wakes up at 5 a.m. on weekdays. He dresses, reads some Bible passages and arrives at the Jets’ complex here by 5:45. When he enters the locker room, none of his teammates are inside, not even his fellow receiver Brandon Marshall, who was astounded to discover that someone could beat him there.
After stretching and soaking in a hot tub, Thompkins runs routes in the field house with the backup quarterback Geno Smith. Until he catches 300 passes, Thompkins does not leave.
“Just to get my hands ready for the day,” he said.
Thompkins finds comfort in the routine, and the routine gives him purpose. It centers him.
He receives few snaps with the first-team offense but prepares as if he will start. If he plays, he will be ready. That is what he promised himself, and it is what the Jets have learned about him.
In the first half last week against Dallas, Thompkins identified a coverage he felt he could exploit. He told quarterback Ryan Fitzpatrick about it, then hoped the Cowboys would show that look again. They did, with about a minute remaining and the score tied, and when Dallas defensive back Byron Jones turned inside, Thompkins zoomed past.
The Jets are 9-5 and chasing a playoff spot because of Fitzpatrick’s resurgence and Marshall’s brilliance and Muhammad Wilkerson’s dominance, but also because they have maximized the bottom of their roster. The backup safety Rontez Miles’s interception near the goal line Dec. 6 against the Giants, which facilitated a fourth-quarter comeback, was the defensive equivalent of Thompkins’s 43-yard reception, which set up the winning field goal against Dallas.
“If he drops that ball, I mean, he could potentially never play again for the Jets,” Marshall said by his locker the other day. “That’s what happens when you’re fourth, fifth on the depth chart. That’s just reality.”
He went on: “For me, I drop 10 balls a year, they’re going to keep throwing to me. A guy like Kenbrell, you drop that ball, it could be your last.”
Thompkins’s role in that victory, the Jets’ fourth straight, not only affirmed his place on the team — he had been inactive three of the previous four games — but afforded him some measure of satisfaction heading into their rematch Sunday against the Patriots, twice his former squad.
Although plenty of figures in the rivalry have switched from one team directly to the other, from players (Darrelle Revis and Curtis Martin) to coaches (Bill Belichick and Bill Parcells), New England has had far more success squeezing production out of players discarded by the Jets — Danny Woodhead, Jermaine Wiggins, Bobby Hamilton among them — than the other way around. Thompkins, for the Jets, is a welcome exception.
“You go back and look at his history, a rookie playing in New England, he was able to come in and make an impact so fast because he’s so smart,” Marshall said. “We’ve seen that high football I.Q. throughout the weeks he’s been here, since Day 1.”
The new beginning for Thompkins, 27, came in the first week of October, when he joined the Jets’ practice squad a few days after the Patriots released him from theirs. It was a job in the N.F.L., and he was grateful for it.
What surprised the Jets at first was his speed. He was faster than the offensive coordinator Chan Gailey thought.
The more time Gailey spent around Thompkins, he said, the more he came to recognize, and appreciate, another trait: Thompkins’s awareness. Fitzpatrick respects quick studies, players who are alert and instinctive and sharp, and he trusted what Thompkins told him last week because he had seen examples during practices and games. In meetings, Thompkins pays almost closer attention, he said, to plays in which he is not involved.
“I know there’s a possibility I could be in that spot,” said Thompkins, who was elevated to the active roster on Oct. 20. “I’m going to take that note. I’m going to write that down. And when my opportunity comes, they’re like, ‘K. T. was listening, K. T. heard what I said.’ They see that. That builds their confidence in me.”
Despite catching six passes at Oakland in his first game and four more the next week against Jacksonville, Thompkins faded as coaches worked to integrate the rookie Devin Smith. Sitting out that stretch, Thompkins leaned on his experience as an undrafted rookie with New England in 2013, when he built a strong rapport with New England quarterback Tom Brady — four touchdowns, including a game-winner against New Orleans, in the first six weeks — but played sparingly in the second half. He was released a month into the 2014 season.
“In my mind, I felt like I was working hard, doing all the right things,” Thompkins said. “But you learn.”
He did, but it took him years to achieve that serenity. Growing up in Liberty City, a crime-ridden section of Miami, Thompkins looked for trouble, and it found him. As a boy, he accidentally shot himself in the arm. He sold drugs. He was expelled from high school three times. He was arrested seven times. He spent about a month in jail.
He also fully expected to play in the N.F.L. He just doubted he would make it out of Liberty City.
“Just making mistakes that a young guy would do in the inner city with no guidance,” Thompkins said.
What spurred Thompkins was his younger brother, Kendal, who committed to play at the University of Miami. If Kendal could do it, so could he. A circuitous journey led him, after a two-year stop in junior college in California, to Cincinnati, where Thompkins benefited from a family connection: A cousin, the Steelers all-pro receiver Antonio Brown, vouched for him to his former college coach Butch Jones, who had moved on to the Bearcats.
“A lot of guys who come up with nothing, they’re a little more serious because they know they can lose whatever they worked for,” T. J. Weist, Thompkins’s position coach at Cincinnati, said in a telephone interview. “He knew not to mess around.”
As an example, Weist mentioned how Thompkins, as a junior, spent his spring break in Florida working out with Brown and his N.F.L. friends, a group that included receivers Santonio Holmes, Andre Johnson and Chad Johnson. Academically ineligible at first, Thompkins raised his grades and graduated with a degree in criminal justice that, he said, he hoped not to need for a while longer.
When Weist talks now to his receivers at Michigan, where he is a senior offensive analyst, he often evokes Thompkins. Weist relays what N.F.L. scouts always ask him about a prospect: Does he take care of his body? Does he work hard in the off-season? Does he learn his craft? He cites Thompkins as the paragon.
“My Plan B is to execute Plan A,” Thompkins said. “My Plan A is doing what I’m doing right now.”
That means rising before dawn to begin the regimen that has revived his career, that avenged his release from the Patriots, that has helped save the Jets’ season.
“If you ask me,” Thompkins said, “I feel like I’ve got a lot more in store.”