The NFL took another step toward adopting HGH testing this month when it received a letter from 23 scientists and lab directors from around the world asserting the safety and accuracy of a current test which detects HGH in the bloodstream.

The letter was sent to NFL commissioner Roger Goodell and union Executive Director DeMaurice Smith as further proof that there is no reason to delay the implementation of HGH testing in football.

As part of the new collective bargaining agreement reached this summer, the NFL and players agreed to begin blood testing for HGH, but the union has delayed adopting that specific agreement because it says there is not enough scientific evidence of the reliability of HGH testing.

This newest letter joins an additional letter confirming the validity of the test, providing around five dozen scientists and lab directors worldwide who affirm the effectiveness of the test.

“This further demonstrates that there is simply no excuse for delaying the start of HGH testing in the NFL,” said Greg Aiello, the NFL league spokesman. “The scientific validity of the test is unquestioned. The abuse of growth hormone must be deterred to protect the health of our players and send the right message to young athletes in sports.”

The NFL Players Association has yet to release a comment on the letters, saying it wants to further review the information before issuing a statement.

The Steelers have locked up another young linebacker through 2016. After extending 26-year-old LaMarr Woodley to a six-year, $61.5 million contract earlier this month, Pittsburgh signed 25-year-old Lawrence Timmons Tuesday for $50 million over six years.

In 2010, Timmons had 95 tackles, three sacks and two interceptions for a Steelers team that led the league in rushing defense, allowing just 62.8 yards per game. The team was $10 million over the salary cap at the start of training camp, and could only finalize the deal after restructuring James Harrison and Ben Roethlisberger‘s contracts.

Timmons, who was selected 15th overall by Pittsburgh in the 2007 draft, joins a linebacking corps of Woodley, Harrison, Larry Foote and James Farrior.

Six former NFL players and one current player filed the first ever class-action lawsuit against the NFL over the league’s handling of concussions in Philadelphia on Wednesday.

The players — including two-time Super Bowl champion quarterback Jim McMahon — accused the league of teaching tacklers to lead with their heads, improperly treating concussions and concealing for decades the connections between football and brain injuries. The suit seeks funds for medical monitoring and care.

NFL spokesman Brian McCarthy said that while the league was not yet familiar with the suit, it would fight any claims of wrongdoing.

Another lawsuit against the NFL was filed in Los Angeles in July. In that case, 75 players alleged the NFL has concealed the dangers of concussions since the 1920s. That lawsuit also includes official NFL helmet manufacturer Riddel.

Because this new lawsuit is a class-action suit, however, it could potentially include any player who has ever suffered a concussion or head injury in the NFL.

“Our goal is much larger, perhaps more daunting,” said the players’ attorney, Larry Coben.

The other six plaintiffs are Browns offensive tackle Joe Thomas; Mike Furrey, 34, wide receiver for four NFL teams since 2003; Wayne Radloff, 50, former Falcons and 49ers offensive lineman; Gerry Feehery, 51, former Eagles center; Ray Easterling, 61, former Falcons defensive back; and Steve Kiner, 64, former Cowboys linebacker.

The position of NFL referee has been completely exclusive to men in the past, but Carl Johnson, the league’s vice president of officiating, told ESPN.com that he plans to hire a female official in the near future.

“We have some in our pipeline, and I expect we’ll see it soon,” Johnson said. “Our goal is to get the best people working this game.”

Sarah Johnson and Terri Valenti would appear to be the most likely candidates. Johnson is a Conference USA referee and was the first woman to officiate a major college football game, and Valenti became the first female referee in pro football at a UFL game last year.

“Any professional sport is at the highest level, and if they asked me to officiate at that level, I would not turn them down,” Thomas said.

In an effort to replace the NFL’s complex, 38-year-old quarterback rating system, ESPN plans to unveil its new Total Quarterback Rating during a TV special this Friday night.

In the current quarterback rating system, 158.3 is a perfect score. The new model plans to make 100 a perfect rating, and 50 an average rating. This ranks Tom Brady, Peyton Maning, Matt Ryan, Aaron Rodgers and Drew Brees as the top quarterbacks in the league, and puts Derek Anderson, Brett Favre and Jimmy Clausen at the bottom of the list.

Total QBR will reportedly account for everything a quarterback does (other than handoffs), including running, sacks, fumbles and penalties. The current system only takes completion percentage, touchdowns and interceptions into account.

A new study presented Monday at the Alzheimer’s Association International Conference in Paris shows that retired NFL players are more likely to develop mild cognitive impairment (MCI), a pre-Alzheimer’s form of dementia, Time magazine’s Alice Park reports.

Unlike the effects of multiple full-blown concussions — whose connections to the degenerative neurological condition known as chronic traumatic encephalopathy have been heavily publicized — mild cognitive impairment has been linked to lower-impact hits, even those sustained in practice.

“It’s conceivable that by changing the ways players drill in practice, we could change things,” said Christopher Randolph, professor of neurology at Loyola University Medical Center.

Randolph said that blows to the head can split or tear the fibers linking nerve cells in the brain that enable higher-level thinking and memory. The brain builds up a reserve of backup cells, but repeated blows to the head can deplete that reserve.

Randolph also said helmets may prevent skull fractures, but the traumas that lead to MCI occur when the brain slams into the inside of the skull, something helmets can’t prevent.

The results of this study — which compared cognitive functions of retired players with healthy non-athletes of the same age and non-athletes of the same age diagnosed with MCI or Alzheimer’s Disease — are only preliminary, Randolph said. Future testing will need to take into account obesity, hypertension and diabetes, as well as genetic factors, all of which can lead to MCI.

Whether or not the NFL has a season in 2011, Chad Pennington will not be playing. The oft-injured quarterback told the Daily Mail of West Virginia that he will skip the season and “do some work for Fox Sports.”

As the only player to win two NFL Comeback Player of the Year awards, the 34-year-old Pennington expressed concerns about his injury history.

“I’m going to evaluate things and see where I am physically,” he said. “It seems like I majored in [injury comebacks]. I’m trying to get away from that. It seems to follow me around.”

During his 11-year career, Pennington suffered four shoulder injuries, a fractured hand, and an ankle sprain. Most recently, he tore his ACL during a pickup basketball game.

Los Angeles hasn’t had an NFL team since the Rams left in 1994, but NFL.com reports the city is inching closer toward getting another franchise.

AEG, one of the companies with plans to build a stadium in Los Angeles, said that if the NFL agrees on the “right CBA,” the project could kick into another gear. At this point, no team in the NFL is guaranteed to relocate, but the company has named the Jaguars, Vikings, Raiders, Chargers and Rams as potential options.

In an effort to address player safety in the NFL, the league is looking into a new “team fine” system for teams that have multiple players who are fined throughout the season.

The plan is not official yet, but plans are in the works. “We’re still working on specifics. Let’s just say it would be significant and reasonable,” league vice president Adolpho Birch said.

“As a club’s total [number of fines] increases to a certain threshold, we will enforce some … payback to encourage clubs to stay below that threshold,” he added.

Also, at the owners meetings in Indianapolis, NFL VP Ray Anderson said that suspensions would again be considered for hits that are considered flagrant violations. It was also noted that fines and suspensions would be easier to come by in 2011.

For the second time in 15 months, Peyton Manning had neck surgery. The procedure took place Monday in Chicago and Manning told The Indianapolis Star Tuesday that the procedure was “minimally invasive” and he expects to make “a quick recovery.”

In March of 2010 Manning had neck surgery to try to get rid of problems a pinched nerve had caused for about four years. According to Manning, this procedure was completely different from 2010. He said this surgery was to repair a disk-related issue that has caused discomfort recently.

“There is plenty of time for recovery,” Manning told The Star.

Colts owner Jim Irsay also is not concerned about Manning being out for an extended period of time. “It’s usually a 6-8-week recovery period,” Irsay said. “I think this is one you can bounce back from quickly.”