PHOENIX -- As the Milwaukee Brewers take the field for an early Cactus League game, third baseman Corey Koskie holes up indoors with only the clubhouse attendants for company. He hasn't stepped in a batter's box with something at stake for eight months, and his workout routine is more befitting your Uncle Pete at the assisted living facility than a finely-tuned professional athlete.
Today's schedule calls for Koskie to ride a stationary bicycle for 10 minutes, elevate his heart rate to 110 beats per minute, then retire to the background noise of ESPN on the clubhouse television. After a suitable passage of time, he'll climb on the bike and do it again.
That's 20 minutes, total. A full day's work.
Koskie was sitting at his locker recently when pitcher Chris Capuano came into the clubhouse after a long, hard workout. Capuano's shirt was drenched, and Koskie was overcome with perspiration envy.
"I can't wait until the day I can do that -- come in from the field and have a sweat on like that,'' Koskie says. "That's the hardest part. You can be here with the guys, talking and joking and doing all that stuff. Then they put on the uniform and go outside, and you have to stay in here.''
Post-concussion syndrome, the malady that's forced Koskie into this protective cocoon, has taxed his patience and put his emotional endurance to the test. The doctors tell him he's making progress, and it appears to be only a matter of time before he resumes his career. Until then he must live with incremental progress, and the realization that even some teammates might question the severity of his condition.
"My arm isn't in a splint,'' Koskie says. "My wrist isn't in a cast. Just because people can't see something visually they might think, 'What's his deal? Why can't he just push through this?' But I know what I feel. Just because somebody thinks that, I'm not about to put the rest of my life and my family in jeopardy.''
Head trauma is a way of life in professional football, hockey and boxing, where violent collisions and brain-jarring action are part of the attraction for the ticket-buying public.
Baseball isn't meant to be a contact sport; sometimes it just works out that way. When Pete Rose bowls over Ray Fosse, Tony Conigliaro takes a Jack Hamilton pitch in the face or a line drive ricochets off Matt Clement's head into left field, it reminds us of the inherent risks and fragility of a skill sport gone awry.
Last year alarm bells suddenly went off when three high-profile major leaguers were in the news for events outside the norm.
St. Louis outfielder Jim Edmonds suffered a concussion on June 21, when he hit the wall in pursuit of a home run by the White Sox's Joe Crede and his head slammed into the warning track. Edmonds eventually missed a month amid bouts of dizziness and blurred vision. He remembers driving home from the ballpark and missing exits and having difficulty reading street signs. He still suffers from headaches regularly.
Edmonds looks around the St. Louis clubhouse and guesses that just about every player might have suffered a concussion at some point. He points to second baseman Adam Kennedy, who is a perpetual target for takeout slides and aggressive baserunning in the middle of the infield.
"That's just the way it is to be a professional athlete,'' Edmonds says. "You're taught to be a machine, but sometimes machines break down, and there are all kinds of reasons why.''
The stakes were raised in February when Giants catcher Mike Matheny retired because of concussion-related issues. Matheny is best known for his four Gold Glove awards, but he was revered in the clubhouse for his team-oriented mind-set and high pain threshold.
"Mike Matheny is the toughest player I've ever played with, hands down,'' says Brewers outfielder Geoff Jenkins. "I saw him get hit in the face with a ball from Julian Tavarez and he wanted to play the next day. For him to shut it down, he must really be messed up bad.''
While Matheny's problems were apparently the result of one too many collisions and/or foul tips to the mask, Koskie can trace his issues to a single incident. While pursuing a pop fly off the bat of Cincinnati's Felipe Lopez on July 5, he flipped, landed awkwardly and suffered a case of whiplash.
Koskie has seen the replay "500 times,'' and the play still looks relatively benign in hindsight. Unfortunately, that wasn't true of the consequences. As days turned to weeks, then months, Koskie entered a bizarre world of memory lapses and inexplicable blackouts. The only thing missing was a Rod Serling narrative.
Koskie took his kids to Wal-Mart and was so tired he could barely make it to the parking lot. He bumped into walls and banged his hands on the dinner table while reaching for the salt and pepper shakers. And when he watched TV and the screen got busy -- say, during a hockey game or the show "24" -- the stimuli would overwhelm him, and he would have to retire to a dark room and lie down until the dizziness and nausea subsided.
"That's just the way it is to be a professional athlete. You're taught to be a machine, but sometimes machines break down, and there are all kinds of reasons why."
-- Cardinals outfielder Jim Edmonds
Driving became a major ordeal because of the pressure that built up in Koskie's head from the moment he turned on the ignition. Here's something even scarier: Koskie would drive from Point A to Point B, but couldn't remember making the trip.
This spring, Brewers broadcaster Bob Uecker approached him and said, "I knew you weren't right when we talked in Arizona.''
"We talked in Arizona?'' Koskie said.
"Yeah,'' Uecker says. "We had a conversation for 15-20 minutes.''
Koskie channeled his energy into finding answers. He searched obsessively for information on the Internet, even though too much time on the computer triggered his symptoms. He spoke by phone with Matheny, NHL players Jordan Leopold and Tim Connolly, and the father of Eric Lindros, whose career was nearly destroyed by concussions.
The road eventually led Koskie to Dr. Mickey Collins, a specialist at the University of Pittsburgh, who spent hours interviewing him. Collins told Koskie that his symptoms were a "textbook'' example of post-concussion syndrome.
Koskie later visited the University of Buffalo, where the doctors put him on a graded program marked by several stages of exertion. The steady, systematic approach seems to be working. The Brewers says Koskie is 50 percent ahead of where he was a month ago in his workout program.
While Milwaukee will begin the season with Craig Counsell and Tony Graffanino at third base, Koskie is confident he'll be playing again at some point. But he and the Brewers have refrained from setting timetables and risking a setback.
"We're hopeful he'll play,'' said assistant general manager Gord Ash, "but we're trying to stay away from putting expectations on him. We just have to continue to be patient and let nature take its course.''
Baseball, in the meantime, is making significant strides in dealing with the problem. Even though standard tests such as MRIs and CAT scans usually come back normal after players suffer concussions, the sport is becoming more sophisticated in its testing and evaluation systems.
Trainer Stan Conte, who joined the Dodgers this year after 15 seasons in San Francisco, says the old knee-jerk phrases used to describe head trauma have become passé.
"It's no longer a case of 'getting your bell rung,' or 'shaking it off,' or 'dusting off the cobwebs,' '' Conte says. "It's a little more serious than that. There are chemical changes in the brain each time you suffer a concussion. And each time you get another concussion, you increase the chances of the next one.''
As Matheny's ordeal dragged on last season, Conte wondered how many other catchers might be unwitting victims, so the Giants sent a questionnaire to 261 professional catchers asking if they've ever been diagnosed with a concussion.
Only two percent replied affirmatively. But when the catchers were asked specific questions ("Do you ever get dizzy? Do you ever black out? Do you ever have nausea or trouble sleeping?''), suddenly 25 percent said yes.
The Giants looked at equipment and found that catchers masks -- both the standard model and the new-fangled hockey style mask -- do a good job of absorbing the force from foul tips. More clubs are also collecting data these days. About half of baseball's 30 teams belong to the ImPact concussion management program, which provides "baseline'' readings of brain functionality for individual players. The test results give teams a benchmark when players suffer concussions.
It's vital, Conte says, for trainers to be alert in the dugout and teams to exercise restraint in sending players back onto the field too quickly. He's especially attuned to the risks that catchers face because his son, Nick, plays the position in the Dodgers' minor league system.
"The worst thing anybody can do -- a doctor or a trainer -- is put somebody else in harm's way without even knowing it,'' Conte says.
"It's no longer a case of 'getting your bell rung,' or 'shaking it off,' or 'dusting off the cobwebs.' It's a little more serious than that. There are chemical changes in the brain each time you suffer a concussion. And each time you get another concussion, you increase the chances of the next one."
-- Dodgers trainer Stan Conte
As a high profile athlete, Koskie has become a sort of spokesman and role model. He's been corresponding on-line recently with Peggy Gonzales, a Wisconsin woman whose 15-year-old daughter, Allison, was kicked in the face during a soccer game last October.
The Gonzales have visited several doctors, yet Allison continues to suffer from constant headaches, dizziness and fatigue. Out of desperation, the family has resorted to acupuncture in hopes it might alleviate her problems.
"As a parent it has been very frustrating,'' Peggy Gonzales wrote in an e-mail to ESPN.com. "It seems the ultimate care lies in the hands of the professional athletes and should be available to everyone. More doctors should be educated about this condition and be able to offer some advice and information on where to turn for help.''
Koskie's advice to youth athletes with concussions is simple: Despite the urge to work harder, they have to understand the importance of pulling in the reins.
"I would tell kids, 'Don't try to push through your symptoms. What you're feeling is real,' '' Koskie says.
Koskie has three boys age 2, 4, and 6, and loves to play floor hockey with them in the family basement. The little one, Caleb, gets frustrated when his father has to go upstairs for a break. But the oldest son, Bradley, understands.
"He tells me, 'OK, Dad. When you stop feeling dizzy can you come back and take some more shots at me,' '' Koskie says.
Dad is getting better, day by day, but some things simply can't be rushed. Koskie's sons, his teammates and Milwaukee management are in the same holding pattern. They're all waiting for the day when Corey can come out and play.