After four injury-filled seasons as part of a crowded group of receivers in Seattle, D.J. Hackett came to Carolina with the promise of more playing time.

One training-camp punch likely left Hackett the Panthers’ opening-day starter — if he can stay healthy.

Steve Smith’s attack of cornerback Ken Lucas in practice last week changed the dynamic of camp. Lucas suffered a broken nose that will require surgery, Smith was suspended for the first two regular-season games, and Hackett emerged as Smith’s likely replacement in Week 1 at San Diego.

“I don’t think it’ll be that big of a difference for me,” Hackett said of filling in for the Panthers’ top receiver. “I’ll still be doing the same position. We’ll just have one less playmaker on the field.”

Hackett has had trouble staying on the field his entire career, and Wednesday was no exception. He limped off midway through the morning practice with a toe injury. He was later carted to the locker room, and while coach John Fox didn’t believe the injury was serious, it’s another reason to question Hackett’s durability.

A fifth-round pick of the Seahawks in 2004, the 6-foot-2 receiver didn’t get into a game as a rookie thanks to a hip injury. He missed the first three games in 2005 with a knee injury. He sprained his right ankle in the 2006 playoffs and missed Seattle’s NFC divisional loss to Chicago.

Hackett injured his right ankle in the season opener last year. Just when he was getting healthy, he hurt it again, limiting him to six games and 32 catches in the regular season.

“It was real tough, especially since it was about the third series of the first game when I first got hurt,” Hackett said. “So it was tough to handle.”

Hackett also faced steep competition in Seattle with Deion Branch, Bobby Engram and Nate Burleson. Even though he caught six passes for 101 yards and a touchdown in Seattle’s NFC wild-card win over Washington in January, the Seahawks had little salary-cap room to re-sign him.

Coming to Carolina, where Smith has had little help since 2004, intrigued Hackett. So did changing from the short-pass West Coast offense to Carolina’s down-the-field style.

“This offense you have a little bit more freedom on your routes, at the top of your routes, to do different things,” Hackett said. “In the West Coast, it’s more about timing.”

Hackett signed a two-year, $3.5 million deal. The Panthers also brought back Muhsin Muhammad, who they hadn’t effectively replaced since he left for Chicago in 2004.

The duo was supposed to give the Panthers more options after Smith. But after the three-time Pro Bowl selection’s lack of judgment Friday, they’ll likely both start against the Chargers and in the home opener a week later against Chicago.

“I like D.J. He works hard,” safety Chris Harris said. “He’s got excellent hands. Any time the ball is near him it seems like he’s coming down with it. He makes the tough catch. I’m excited that he’s on my team and I’m ready to see what he does in live action.”

Fox has had Smith work with the starters since he returned to practice, but acknowledged he’ll eventually move him to the second team to prepare for the first two games.