FLORHAM PARK, N.J. — Darrelle Revis walked off the field thinking he just had a headache — until he started feeling a bit strange.

The New York Jets cornerback suffered what the team called a “mild concussion” — the first of his football career at any level — and it caught him by surprise.

“It’s been a fog, like being in a fog,” Revis said Thursday, speaking about his injury for the first time. “I’ve never had a concussion, so this is something you’ve got to get guidance from the training staff and the doctors.”

The Jets will make a decision on Revis’ availability before the team travels to Pittsburgh on Saturday for their game Sunday against the Steelers.

“I feel good,” he said. “I feel pretty good. I feel like I could play this week, but there are some other procedures we need to do and guidelines we have to follow.

Revis has been able to run and lift weights, and attend meetings all week. He added that the foggy feeling he experienced earlier in the week has dissipated, and he hasn’t had any sensitivity to light — a common side effect of concussions.

“It’s cool,” he said before laughing. “I know who you are.”

Revis spent practice Wednesday and Thursday on the exercise bike on the sideline. He has been cleared for physical activity, but not contact. The team will monitor Revis the rest of the week, and if he isn’t cleared by Saturday, he won’t fly to Pittsburgh with the team.