HEMPSTEAD, N.Y.- New Jets running back Kevan Barlow has barely slept the last two days.

Who can blame him? He was in Oakland, Calif., for a preseason game Sunday when the 49ers told him they traded him to New York. Barlow was stunned. It was only days earlier that coach Mike Nolan reassured him that he had a future in San Francisco.

So Barlow packed up the few items he had and took a red eye to New York, landing early Monday morning. From the airport, Barlow went to take his physical – and passed – before joining his new teammates for the afternoon practice.

He watched most of it, participating in only a few drills. Barlow also got his first glimpse of Chad Pennington, who returned to practice after going home to Tennessee to be with his ailing father and missing last weekend’s preseason game against Washington.

Though Barlow was tired, his adrenaline and excitement carried him through the day.

“I was really shocked. I wasn’t expecting it,” Barlow said. “I’m still kind of in a blur right now. Everything happened so fast. Just (Sunday) I’m getting ready to play the Raiders, now I’m here in a Jets uniform. It’s good, though. I’m excited about the opportunity I have to come out here and play.”

Even better for Barlow: bolstering a running back group struggling without Curtis Martin, who has been unable to practice because of a lingering right knee injury. Though the 33-year-old Martin insists he wants to play this season, the future is uncertain.

Barlow idolized Martin as a child. He grew up in Pittsburgh and went on to play for the Panthers in college, same as Martin. When Barlow showed up at the Jets facility Monday, Martin sat him down for a chat.

“There was no one bigger than Curtis Martin in Pittsburgh,” Barlow said. “We were talking before I came out here, and I was in awe, like, ‘Man, I’ve got Curtis Martin, Hall of Fame running back, sitting next to me. I’m ecstatic about it.”

Barlow does come with some baggage. After gaining a career-best 1,024 yards in 2003, he seemed unsuited for the pressure and workload of a full-time starting job in 2004. Barlow managed 822 yards.

He had another dismal year in 2005, running for 581 yards with a career-low 3.3 yards per carry. Barlow also had some spats with teammates and coaches, including a long-running feud with fullback Fred Beasley. The players quashed their fight last season.

Barlow dismissed the questions, saying he was a “great character guy.”

“I had some issues as a rookie with Fred Beasley, but that’s behind us,” he said. “Me and Fred are best of friends right now. It was a situation, I was 21 years old, he was a veteran and he wanted things to run a certain way and I had to get accustomed to that. But like I said that’s behind us.”

“When we brought Bryan Cox in here in ’97 or ’98, there was a lot of talk about the way that he was and the problems that he had,” Mangini said.

“I can tell you he was one of the best guys I have ever worked with. … I feel really comfortable with the research we’ve done on Kevan.