NFL teams are not required to file official injury reports for exhibition games.

But if they did, the Panthers would list receiver Steve Smith as out.

Smith remained on crutches Friday with a foot infection that will keep him out of Sunday’s game against the New York Jets. Panthers coach Ron Rivera gave no timetable for Smith’s return, and reiterated he’s uncertain how the infection developed.

“All I know is he got an infection,” Rivera said. “It could be from a scratch or something.”

The infection developed after last week’s exhibition win against Miami. Smith is being treated with antibiotics, and has swelling in the foot.

With Smith out, Brandon LaFell becomes the No. 1 receiver. Rivera said Louis Murphy or Seyi Ajirotutu would start at the other wideout spot.

Murphy, acquired from Oakland in July, caught two passes for 29 yards in the 23-17 win against the Dolphins. Murphy added a 31-yard rush on an end-around.

Ajirotutu, a special teams player last season, had one reception for 6 yards versus Miami. Ajirotutu also dropped a pass on a crossing route.

DAVIS BACK: Outside linebacker Thomas Davis will play against the Jets – his first game action since a Week 2 loss to Green Bay last year, when he tore the ACL in his right knee a third time. Davis injured his right calf during the second training camp practice, and sat out the first two exhibition games.

Rivera said he is excited to see Davis, listed as rookie Luke Kuechly’s backup on the weak side, in a game. Davis began the week working on special teams but was getting reps on defense by week’s end.

“He’s had a really good week and, knock on wood, it continues,” Rivera said. “He’s done some really good things as far as getting right back in the flow. We’ve increased his reps, done more with the base stuff, which was not our initial plan. But he’s looked so good, we’re real excited about it.”

Middle linebacker Jon Beason, who ruptured his Achilles in last year’s opener, remains out with a hamstring injury. When camp broke last week, Beason said he hoped to get in an exhibition but was targeting the Week 1 game at Tampa Bay.

NEBLETT IMPROVING: Rivera said the medical issue that has sidelined defensive tackle Andre Neblett the past two weeks is hypertension, along with anxiety and fatigue.

“Basically, he had high blood pressure really bad,” Rivera said. “So he had to come in, and they had to stabilize him.”

Rivera said Neblett could be back soon. Neblett, an undrafted free agent in 2010, is suspended the first four regular-season games for testing positive for a performance-enhancing drug that he said was a dietary supplement.

Neblett is eligible to practice and play in preseason games before the suspension begins. He will not count against the 53-man roster while suspended.

GAME ON: Left tackle Jordan Gross said there was a different vibe at practice this week as the Panthers prepared the starters for their most extensive action of the preseason. The first-teamers could play into the third quarter against the Jets.

“You can tell just by watching practice we’re getting a lot more reps with the (first team),” Gross said. “It’s a lot more serious about our schemes and our stuff against what the Jets are doing.”

Rivera said he wants to see fewer penalties after the Panthers were whistled 17 times for 145 yards against the Dolphins.