CHARLOTTE, N.C. — Want to know what can happen when you run out of cornerbacks?

It's last Sunday, and the Carolina Panthers are playing the Giants. New York has a third down-and-goal at the Carolina 3, and the Panthers, with three of their top four corners nursing injured hamstrings, have moved veteran safety Mike Minter to cornerback in their nickel (three corners) alignment.

"It screwed up one of our safeties," coach John Fox said Thursday. "Because he thought Minter was the safety, but he was the nickel. So he lined up as if Minter was the safety, and that guy on that pop pass was wide open."

That guy would be wide receiver David Tyree, who caught an unimpeded touchdown pass from Eli Manning.

"When you haven't practiced that way all week; you've practiced the other way, you become instinctual," Fox said. "And unfortunately that hurt us."

Carolina is hoping for improvement Sunday, when the Panthers meet Pittsburgh in Bank of America Stadium. And things looked up a bit at Thursday's practice, when starting corner Ken Lucas returned to work.

"I felt like a kid in a candy store being back out there," he said.

Hamstrings, though, are notoriously unreliable once they've been tweaked, so Lucas is hardly a certainty for Sunday.

Meanwhile, fellow starter Chris Gamble missed practice again. And backup Christian Morton, who pulled his hamstring early against New York, has been lost for the remainder of the season.

All of which sent the Panthers scrambling for reinforcements. Tuesday, they signed free agent Derrick Strait, who was last in Charlotte in 2003, when he won the Bronco Nagurski Award.

Strait, who had already made brief stops with four other teams this season, could find himself working as the fourth corner after three days of practice with his new team. Should Lucas have a relapse, he could be No. 3, behind rookie Richard Marshall and former Tampa Bay practice squad member Dion Byrum.

"I got here on Tuesday, came straight in, got into the playbook and tried to learn everything I could," Strait said. "I've just been trying to soak it all in and learn everything anyway, whether they tell me (I'm playing) or not, I'll just be ready."

Which isn't that easy.

Cornerbacks have a lot to do besides playing man coverage on wide receivers. They have to know their responsibility in zone alignments, how to run the corner blitz and be able to offer run support when needed.

"We call on our corners to tackle," Minter said. "Our corners are in the run game a lot. Does that affect it? It affected us Sunday. It wasn't that they played so poorly, it's just communication."

Should Lucas not be able to play, the rookie Marshall would be the most experienced corner on the field.

"When it was just Chris and Ken and me in there, we knew where we were going," Marshall said. "We've just got some new guys, and we've got to get together, get a bond and chemistry together and be ready to play."