With a late-season game on the line, Green Bay Packers quarterback Aaron Rodgers exits with a concussion and doesn’t return. Pittsburgh Steelers tight end Heath Miller and Arizona Cardinals quarterback Derek Anderson sit out games altogether because of head injuries.

And those are only a few examples from this Sunday. If it seems as though more and more NFL players are missing time because of concussions, it’s because they are: According to league data obtained by The Associated Press, the number of concussions being reported this season is up more than 20 percent from 2009, and more than 30 percent from 2008.

The NFL considers that proof that players and teams are taking head injuries more seriously and being more open about them. The players themselves agree.

“A lot of it is changing the culture. Guys are more open to reporting them, and they know more about the effects and how dangerous they can be in the long term,” said Oakland Raiders tight end Zach Miller, who got two concussions last season. “Guys are making smarter decisions.”

The NFL’s data shows 154 concussions — from practices or games — were reported from the start of the preseason through the eighth week of the 2010 regular season. That’s an increase of 21 percent over the 127 concussions through the eighth week of the 2009 season, and a 34 percent jump from the 115 reported over the same span in 2008.

Dr. Hunt Batjer of Northwestern University, co-chairman of the NFL’s head, neck and spine medical committee, called the numbers “a great sign.”

“Based on the opinions of the trainers and the team physicians and everyone we communicate with, it appears to be a cultural change,” Batjer said in an interview with the AP.

“We’re trying to make sure that players have the message: Playing through pain is good; playing through pain is what sports are about. But that’s leg pain. That’s arm pain. Not brain injury,” Batjer said. “Because a brain injury and spine injury can threaten their future.”

Concussions continue to be a hot-button issue for the league and its players. Batjer’s committee met for two days in New York last week to gather information about improving player safety and consider steps to take moving forward; the union’s traumatic brain injury committee is convening Monday and Tuesday in Washington.

“We have educated players. … It’s not a failure to sustain an injury, and you’re not letting down your team if you report your injury,” said former NFL player Sean Morey, a co-chairman of the union’s committee. “When you raise the level of awareness, and players are educated, then I think they have an ability to communicate with their trainers. They don’t feel like they’re letting down their team.”

Every week, key players are sitting out.

Rodgers was slow getting up after being hit by two Lions at the end of a scramble in the first half of Green Bay’s 7-3 loss at the Detroit Lions. After Green Bay took a timeout, Rodgers was sacked on the next play. He stayed in for the rest of the drive but then left for good.

“He was a little groggy after those two plays, and the medical staff and Aaron decided it was in his best interest not to go back in,” Packers coach Mike McCarthy said.

Packers receiver Donald Driver said that he encouraged Rodgers to consider leaving the game.

In discussing Rodgers’ injury, Dr. Thom Mayer — the other co-chair for the union’s committee on the issue — said he wonders how often players have stayed in games despite absorbing the sorts of hits Green Bay’s QB did.

“How many times did that occur in the past, and no one stepped up to say, ‘Something’s not right with this guy’? … What did they put on the line without even knowing that they were putting it on the line? How many thousands — tens of thousands — of times has that occurred before now?” Mayer said. “And the answer is: We’ll never know. Records weren’t kept the way they are now.”

The NFL and union have been working to get players to think about head injuries differently from other health problems, hoping that players will not only be more vigilant about reporting their own symptoms but also about keeping an eye out for teammates who might have a concussion.

And perhaps that all is working.

“The bigger emphasis on it has helped,” Oakland’s Miller said. “There was information out there, but not as much as we have now, and not as much as guys talking about it. Trainers are looking for it. You see a guy get up woozy and you know something is wrong with him. Guys aren’t trying to hide it as much.”

Thirty of 160 NFL players surveyed by the AP in November 2009 replied that they have hidden or played down the effects of a concussion.

“That’s one good thing (Commissioner) Roger Goodell and the NFL have been doing: The message is that if there’s something wrong with a guy, especially a head injury, you don’t want to rush a guy back or make a little mistake that could mess him up, possibly for life,” New York Jets safety Brodney Pool said.

“I think they’ve been doing a good job of getting things under control and making it harder for guys to get out there,” Pool said. “I mean, this is the guys’ passion, and you want to go out there. You can say, ‘Nah, nothing’s wrong with me,’ but deep down inside, you know something’s wrong.”

Seattle Seahawks cornerback Marcus Trufant, who got a concussion in a game last month, has seen a change in the way head injuries are handled.

“It’s more of an active approach from the trainers and the league of the stuff you have to go through after you’re diagnosed with a concussion. It’s not like, ‘He’s a little woozy in the game; we’re going to see how he feels,’” Trufant said. “If you’re woozy or if they see any symptoms of concussion, you have to come out and go through all these tests before you can get back on the field.”

In December 2009, the NFL set up new rules for checking players on the sideline during a game to determine whether they have a concussion or can get back on the field. Last week, Batjer’s committee discussed adopting a league-wide exam so each team would perform the same tests on a player who might have a head injury.

“A couple of team doctors mentioned to me that players in the past would have gone back in had it not been for our return-to-play guidelines. That’s a positive thing,” Goodell said. “But one of the things we’ve got to do is make sure there’s an awareness out there, so that when a player gets an injury, they report the injury to our medical professionals so they can be evaluated and those determinations can be made from a medical standpoint.”


AP Sports Writers Dennis Waszak Jr. in Florham Park, N.J., Larry Lage in Detroit, Tim Booth in Seattle, Josh Dubow in Alameda, Calif., and Chris Jenkins in Green Bay, Wis., contributed to this report.