Mike Westhoff didn’t want Brad Smith to leave.

The Jets special teams coach fought with team executives, urging them to shell out the money required to retain their vaunted return man in the offseason. But the Jets wanted to allocate their resources elsewhere, so Smith bolted, signing with the Bills.

Smith was one of Westhoff’s favorite players he’s ever coached, which made losing him difficult. But Westhoff didn’t have time to grieve.

After all, as the sign that hangs in his office inside the team’s practice facility says, “You can’t win with the players you don’t have.”

And Westhoff truly believes it. He has so much confidence in himself and his system, that he feels like he could throw almost anyone in and it would work.

Case and point: Through the first five weeks of the season, no kick returner in the NFL has better numbers than Joe McKnight.

McKnight, thrust into regular duty after Antonio Cromartie hurt his ribs in late September, leads the league in yards per kickoff return (45.6) and is tied for the league lead in touchdowns (one).

Last week, McKnight broke off an 88-yard return in New England; and two weeks ago, there was the 107-yard TD return in Baltimore.

“I just have a lot of confidence in my blockers,” McKnight said. “They’ve never let me down, so I don’t want to let them down.”

The reason Westhoff’s units have been so successful, he says, is because all of his players understand the basics.

“We break everything down into components,” Westhoff said. “We teach you have to double-team, how to set, how to trap, how to roll, how to wedge, how to read, how to lead [and] how to seal. There, I gave you the whole darn thing in two seconds. ... It’s not that hard.”

Westhoff normally draws up 15 different kickoff return formations per week. On Monday night against Miami, he expects to use about three.

The Jets practiced kickoff returns for four minutes on Wednesday, three minutes on Thursday and one minute on Friday.

“We have a solid system,” Westhoff said. “And if we practice it right and block it the right way we always have a good chance [to break one].”

Westhoff says there’s still work to be done, but the Jets have certainly shown themselves to be an explosive kickoff return team, so much so to the point where teams are likely going to start kicking away from them.

Westhoff thinks teams could start blasting the ball out of the endzone or kick the ball toward the corners when the weather gets cold in an attempt to pin them deep in their won territory.

Still, he gives his returners a lot of leeway.

“If we believe it’s a ‘returnable ball’ we’re prepared to take it out,” Westhoff said.

According to McKnight, seven-eight yards deep seems to be the cutoff.

“I mean, it’s frustrating [if they kick the ball away from you or out of the endzone],” McKnight said. “But it lets you know the kickoff return team is doing something special.”

After getting tackled before getting into the endzone in New England, Westhoff and McKnight had the following exchange:

“When I got caught from behind, the first thing he asked me was, ‘What happened?’” McKnight said. “I was like, ‘What do you mean?’ He’s like, ‘Did you get tired?’ I was like, ‘No.’ ... I was just trying to make moves to try to avoid people, that’s probably why I got caught.’”

Said Westhoff, “It’s my responsibility to make the most out of what we have, and I believe that we have some talented guys.

“We’ve had quite a number of guys we’ve changed like our guards. We lost Rob Turner, he was our best big wedge guy. But we threw Mully [Matt Mulligan] in his place. Jeff Cumberland, I just think that guy was gonna be off to the races as a football player. He had a very intricate role. But we’ve got a bunch of interchangeable parts on this team.”

Up and down: T.J. Conley has drawn the usual rookie review from Westhoff.

“Up and down,” the Jets special team coaches said when asked about his first-year punter. “I’ve seen some excellent punts and some very quality punts that I would be happy with from anyone, and then I’ve seen some others that I’m not very happy with.”

Conley does rank fifth in the NFL in punts inside the 20 with nine.

Backing up: Westhoff said Mulligan is his backup long-snapper. He also said Nick Mangold can do the job.

Starter Tanner Purdum missed practice earlier in the week with a lower back injury, but is probable.

We tease him a bit,” Westhoff said of Purdum. “The reason his [back] muscles were cramping up and sore is because all of a sudden he’s got muscles.

“He’s really moved in the weight room. you have no idea what this kid’s done to himself.

We told him you never pulled a muscle before because you didn’t have any. He has them now.”