Jeremy Kerley vowed last month to investigate how he could have failed a test for performance-enhancing drugs that led to a four-game suspension. Apparently, the Jets wide receiver decided he needed to call the Ghostbusters.

Kerley, who returned from the suspension Wednesday, made light of the situation when asked how he believes a banned substance got into his body.

“I don’t know,” Kerley said. “There’s a lot of ghosts around here. Maybe a ghost put it in me. You know the Ghost of Christmas Past? A ghost might have put it in me. I don’t know.”

It was a far cry from Kerley’s strongly worded statement in November when the suspension was handed down.

“While I did not have enough time prior to the deadline to resolve this case, I fully intend to investigate this matter until I am able to figure out what caused the positive test, because I know that I have done nothing wrong,” his statement read.

On Wednesday, though, he dismissed the idea of looking into the matter.

“I ain’t got time to investigate it. It is what it is. I’m back now,” said Kerley, who did deny knowingly using a PED.

The wide receiver returned to practice, but is not back on the Jets active roster yet. The team has a roster exemption until 4 p.m. Monday for Kerley. Coach Todd Bowles said the team has not decided whether to activate Kerley for Sunday against the Saints.

“It’s early right now. We’ll make a decision pretty soon,” Bowles said.

Kerley’s suspension allowed rookie Chad Hansen to play more, something the Jets might not want to stop to bring Kerley back.

Several Jets players said after a 23-0 loss Sunday to the Broncos that the team lacked energy. Bowles disagreed.

“I thought we had more energy this game than we had all year,” Bowles said. “We just didn’t play well. We played hard. We didn’t play well.”

CB Morris Claiborne did not practice Wednesday, saying he needed to rest his injured right foot. Claiborne originally injured his foot Oct. 29 against the Falcons. He said he suffered a little bit of a setback Sunday against the Broncos. Denver WR Demaryius Thomas had a big game against Claiborne, catching eight passes for 93 yards and a touchdown.

“I could have not been limping the whole game,” Claiborne said when asked what he could have done differently. “Ain’t no excuses, man. They got him the ball in big-time situations. When they needed first downs, they went to him. They completed passes and I was the guy who was guarding him. My performance was an embarrassment to myself, this ball club. I know I’m way better than what I put out there last Sunday.”

RB Elijah McGuire (ankle), RB Matt Forte (knee), RG Brian Winters (ankle, abdomen), S Rontez Miles (hamstring) and CB Rashard Robinson (personal reasons) did not practice Wednesday. LS Thomas Hennessy (concussion) was limited.