Vikings' Adrian Peterson back in camp

Adrian Peterson is entering the final year of his contract, and it could be argued that he has plenty of leverage if he wanted to hold out of training camp to force the Minnesota Vikings into getting a long-term extension done.

Peterson insists the thought never crossed his mind.

"I knew when training camp starts, I'm going to be there," Peterson said. "There was no ifs, ands or buts."

The star running back returned to Vikings camp on Friday after missing three days for the birth of his son. He said he is not concerned about his contract status or risking an injury while playing arguably the game's most brutal position.

"I'm not worried about my contract at all. At all," Peterson said, repeating it for emphasis. "My main focus is doing what I can do, learn this offense and help the Minnesota Vikings win the Super Bowl."

He is due to make $10.7 million in base salary after four dynamic seasons helped him achieve every performance bonus in the deal he signed after being drafted in 2007.

Last season he rushed for 1,298 yards and 12 TDs, earning his fourth Pro Bowl berth in as many years.

He also said he regretted a comment he made during the lockout that compared the NFL to modern-day slavery.

"I regret using those words because obviously there's nothing, absolutely nothing, you can compare to slavery," Peterson said. "It stands alone. It was something that I should've used better wording to put that out there."

Chargers sign Floyd to two-year deal

Wide receiver Malcom Floyd is back with the San Diego Chargers.

The team announced it has reached terms with the receiver who led San Diego in yards per catch last year. Terms of the deal weren't immediately available.

Floyd averaged 19.4 yards per catch in 2010 and led the team's wide receivers with 37 catches.

"He was like a human vacuum machine," backup quarterback Billy Volek said. "Any ball that was put his way, he went up and got it."

The Chargers in 2010 were without Pro Bowl receiver Vincent Jackson for training camp and most of the season. Their offense still ended up second in the NFL in both passing yards and passer rating. In his 11 games, Floyd had six touchdown catches, only three fewer than his career total in 51 games before 2010.

Cribbs returns after missing days with injured knee

Josh Cribbs expects to make plays for the Cleveland Browns. He's just not sure in what manner.

Cribbs returned to practice after missing a few days with a strained left knee. He caught a few passes, lined up in the backfield a few times, and even completed a pass.

That's nothing new for the dynamic kick returner. The Browns are always trying to implement his breakaway talent into their offense. A year ago, Cribbs was the key part of a wildcat formation often employed by Eric Mangini, fired as coach after a 5-11 finish.

New coach Pat Shurmur won't be utilizing the wildcat much but intends to try and get the ball into Cribbs' hands as often as possible in other ways.

Panthers add WR Naanee; lose DT Edwards, OT Williams

On the same day the Carolina Panthers officially added former San Diego receiver Legedu Naanee to the roster, the team learned they lost two linemen to injuries.

Naanee has not arrived at the team's training camp. Panthers coach Ron Rivera said Naanee must go through a physical and sign his contract before he can take part in practice. Rivera was hopeful Naanee would be cleared in time for Friday night's practice at Wofford College.

Naanee had 63 receptions in four seasons with the Chargers. He had 23 catches a year ago despite missing six games with hamstring problems.

Defensive tackle Ron Edwards has a torn triceps muscle and rookie offensive lineman Zack Williams has a torn ACL.

Both injuries occurred during practice Thursday. It was not immediately known how long Edwards might be out. Williams is expected to have surgery and miss the season.

Edwards was a free agent from Kansas City who signed a three-year deal worth $8.25 million with the Panthers last week. He has spent 10 years in the NFL, the last five with the Chiefs, with 192 career tackles and 15½ sacks.

Dolphins add former Patriots QB O'Connell

Quarterback Kevin O'Connell has signed with the Miami Dolphins, his fourth team since being drafted in the third round by the New England Patriots in 2008.

O'Connell joined practice Friday as a replacement for Tom Brandstater, who was released.

O'Connell played in two games as a rookie backup for the Patriots. He was with Detroit in 2009, and spent last season on injured reserve with the New York Jets after hurting his throwing shoulder.

The Dolphins have three other quarterbacks -- Chad Henne, Matt Moore and undrafted rookie Pat Devlin.

Bills WR Nelson evaluated after breathing difficulties

Buffalo Bills receiver David Nelson missed practice and was being evaluated in Buffalo a day after having difficulty catching his breath during practice.

Coach Chan Gailey says Nelson is feeling better, but doctors still are attempting to determine the cause of his breathing problems. Gailey says it seems the problem has "calmed down," and he expects Nelson to return to practice within the next two days.

Nelson, who earned himself a third-down role last season, left midway through the Bills evening practice at training camp in suburban Rochester on Thursday night.

Veteran linebacker Shawne Merriman had a "rest day" and watched practice from the sideline.

Tight ends David Martin (toe) and Shawn Nelson (undisclosed injury) both missed practice.

Information from The Associated Press and ESPN NFL Insider Adam Schefter was used in this report.