A week ago, Minnesota Vikings safety Tyrell Johnson took a hit against the Arizona Cardinals so hard he said he couldn’t remember details of the injury.

On Sunday, Johnson was on the sidelines during the Viking’s play-off clinching win against the Cincinnati Bengals. Johnson was one of about 20 players league-wide who missed playing or practice time last week due to head or concussion injuries.

The number of players showing up on weekly injury reports for head or concussion injuries has spiked in recent weeks, from four the week of Nov. 15 to 19 last week.

The increase follows a series of high-profile concussions, and on top of growing awareness of the long-term risks associated with head injuries. Is it just the usual late-season wear and tear, or are teams being more proactive about reporting concussions?

Minnesota Vikings head physician Dr. Joel Boyd thinks it’s probably a little of both.

“I think what we’re seeing is, number one, everybody just responding to what’s out there,” Boyd said.

On Nov. 15, when the Philadelphia Eagles’ All-Pro running-back Brian Westbrook went down with his second concussion in three weeks, it sparked a heightened sensitivity toward concussion injuries, Boyd said. More recently, two high-profile quarterbacks, the Steelers’ Ben Roethlisberger and the Cardinals’ Kurt Warner, also suffered concussions.

On Dec. 2, the National Football League issued a strict clarification of its concussion policy, stating that any players with concussion-like symptoms must be removed from the game.

Boyd said the league’s statement basically outlines the protocols already used by every team he’s aware of, with the exception that it adds a requirement for an independent neurologist to sign-off on players’ recovery before they finally return to play.

Any player knocked unconscious must be removed from the game. A player hit hard but still conscious is examined on the sidelines and pulled from the game if they show concussion symptoms, with a more thorough exam following the game. Any player suspected of a concussion must pass a neuro-psych test before resuming physical activity. After passing that test, they need to complete exercises such as biking and weight lifting without experiencing more symptoms. And they need to prove they can remember plays and instructions in a classroom. All that before returning to the practice field.

“The policy itself doesn’t really change much of what we do,” Boyd said. “It’s just that the NFL wants to make sure that everybody understands we do have a policy.”

In the long run, Boyd doesn’t expect the policy will result in more players appearing on the injury list. The recent emphasis by the league is probably causing over-reporting because teams don’t want to be perceived as ignoring the issue, he speculated.

The league is simultaneously trying to get a message to players that it’s OK to report symptoms. The policy now explicitly encourages players “to be candid with team medical staffs and fully disclose any signs or symptoms that may be associated with a concussion.”

Former Viking Matt Birk said he understands the pressure players toward the bottom of a roster may feel to play through injuries, but also doesn’t understand why others would hide concussion symptoms.

“If your head hurts, how do you play football?” asked Birk. “I don’t know how you would go about playing with that.”

Former Vikings long snapper Mike Morris, currently a host on KFAN, a BringMeTheNews.com radio partner, said he thinks convincing players to report symptoms could be a challenge. In addition to concerns about losing a role on the team, players are also influenced by a culture that tells them to walk it off and get back on the field.

“There’s a part of it that’s very gladiator. It’s very spartan, to continue on and to play when you have been hit all the time,” Morris said. “Your teammates respect that, greatly, and it’s a mark of a player that is pretty special.”

That type of attitude isn’t unique to football, or to men’s sports, said Dr. Diane Wiese-Bjornstal, who teaches a class on the psychology of sports injuries at the University of Minnesota’s School of Kinesiology.

“It’s not a new culture, and in some ways I think it’s better than it used to be,” Wiese-Bjornstal said. “I think athletes are more aware and more careful with their bodies.”

The NFL’s decision to toughen its concussion policy is positive and overdue, she said. While professional players are adults who can make their own decisions, those decisions to play through injuries can be influential to young athletes, she said.

“At the end of the day, these are grown men who can decide for themselves, but I worry more about the trickle down effect to the young athletes who are more vulnerable and who aren’t cognitively mature enough to decide for themselves if they’re willing to take the long term risk,” she said.

“I think it takes a lot more courage to admit you have a concussion and sit out, and take the flak that goes with that, than it does to quote-unquote suck it up and play,” she said. “I think, frankly, the harder thing to do, and the more courageous thing to do, and the more manly thing to do, is to report it. I know guys would probably disagree with me.”

Morris said colliding with other players and “being fogged over, being dazed, being confused” was common during his playing time. If teams start pulling players aside after every collision, it wouldn’t be long before teams run out of players at certain positions, he speculated.

“I don’t know if they’re going to be forced to sit out or not, but if they do, I think you’re going to see a lot of key positions out all the time,” Morris said. He said running backs, wide receivers, linebackers and special teams players are most susceptible. While there’s a larger volume of hits near the line of scrimmage, the higher concussion risk is with players that build up speed before collisions, he said.

His prediction: A lot more players will be sitting out games they probably would not have in the past.

“I think that you’re definitely going to have to pay very close attention to … how it’s going to affect the depth of your team,” Morris said. “The league may have to have a look at allowing a larger number of guys to dress on Sundays.”

“I’m not so sure how this is going to work,” Morris said.

Originally published Dec. 14, 2009, on BringMeTheNews.com.