PORT CHARLOTTE Working out on the field trying to get back from his second concussion in just more than a year was troubling enough for John Jaso. Light running left him dizzy, simple pitch-blocking drills made him want to throw up. • An even more jarring indication of just how bad off he was came when Jaso, a man who hikes mountains for fun, rode an elevator up to the press box for a look down at the Oakland field being converted for football. Suddenly, he found himself gripping a desktop in fear of falling over. • "It's a confusing time," Jaso said. "Our brains are doing a weird thing, messing with our emotions, messing with our sensitivities. And that can drive a person mad." • Jaso was all too familiar with the physical symptoms — the migraine headaches, the vertigo, the queasiness, the inability to focus or even see clearly. But the emotional aspects of the second concussion, the one that cut short his season again last year and altered — after nearly ending — the baseball career that has brought him back to the Rays, was worse. • He was stripped of his usual zeal and zest, left passionless about even his most favorite topics, wrestling with an emptiness he would eventually recognize as depression. • Plus, he was scared. Not as much by what he knew, but what he didn't. • Doctors, trainers, agents, A's officials and coaches all seemed to be ganging up, telling him he needed to think about life after baseball. The implication he might not play again was clear, and the worry only added to the daze that enveloped him. • "It almost feels," he said, "like you're trapped inside of something."The fears from the first concussion, sustained from a series of foul tips to his catcher's mask in July 2013, were rooted in not knowing what to expect.Though guided by the A's medical staff and Dr. Micky Collins, the acclaimed expert at the University of Pittsburgh Medical Center, Jaso and his wife, Shannon, had to work their way through some challenging and uncomfortable days given the tiredness, irritability and sensitivity to light and sound,"I could definitely see changes," Shannon said. "The normal John I was used to, everything was different after that concussion."A's teammate Stephen Vogt, a former Ray, said it was scary to see his friend in such a bad way. "His symptoms were very serious, and they were very present," Vogt said. "You could tell he wasn't quite all there."Healing came slowly, fraught with worry and frustration, though Jaso eventually was clearheaded, and cleared to get back behind the plate, for spring training.But when an August 2014 foul tip off the mask started the cycle over again, Jaso was worse off because he knew what it meant."It was like, 'Oh my God, it can happen again,' " Jaso said. "I thought it was maybe just a freak thing or whatever, and then after the second time it happened, it was like, this is really serious. I don't want to say it's a condition I have or whatever, but my threshold for the impact that I can take, it's a serious thing."Life away from the field was more troubling.Shannon did what she could to help, keeping their home quiet and their dogs away, managing schedules so her husband could rest, sitting up playing board games — Small World and Underworld became their favorites — for entertainment because he was under orders for no visual stimulation.But Jaso acknowledges it was a daily struggle without baseball, or much else normal. His passion for the outdoors and other interests was gone. He wanted to plan an offseason vacation but found nothing appealing. Even simple things he used to enjoy, such as looking at birds fly, didn't do anything for him.Worse were the nights. "Going to bed, being like, 'Oh my gosh, why is nothing working? Why am I not feeling right?' " Jaso said. "That part was really stressful."Though he eventually began to feel better, met again with Dr. Collins (who declined to comment for this article) and talked with other players and the A's staff, Jaso also began to grow more concerned, especially when he got the life-after-baseball speech."My initial reaction is that my life, as far as my career, is falling apart and kind of like ending," Jaso said. "That this is how it ends."•••Though memory loss also has been an issue, Jaso has a decent recall of what led to the two concussions.The first stemmed from a series of foul tips off his wire mask in a July 23, 2013, game at Houston. The second, a little more than a year later on Aug. 8, 2014, when Minnesota's Brian Dozier redirected a Scott Kazmir fastball to hit square on Jaso's mask, the force of impact sending the ball caroming back toward the mound. (Jaso still has the dented mask as an odd souvenir.)Both times he stayed in the game for several more innings.In 2013 he talked his way into playing the next day, but he threw up after warmups, got dizzy during the game, left after seven innings and went on the disabled list the next day, his season over.In 2014 he kept playing for two weeks, pinch-hitting, DH-ing, even getting behind the plate three times before admitting how risky it was: "I was losing sight of the ball out of the pitcher's hand," he said. The next day, that season was done, too."He's stubborn, and he wants to play so bad, and he plays so hard," Vogt said, "that maybe he kind of got in his own way by trying to play through it."•••The January trade that brought Jaso back to the Rays from Oakland as part of the return for Ben Zobrist would have been a good story anyway. Coming up through the Tampa Bay system and a key part of the 2010-11 playoff teams, Jaso was well-liked, known for his long hair, deep thoughts and thick books, plus a mountain man personality, with an occasional dash of Sean Penn/Spicoli.But this deal, even though he and Shannon still live on St. Pete Beach, was much more than a happy homecoming.In acquiring Jaso, 31, to primarily DH (plus log some time in the outfield and maybe first base) but not to catch, the Rays provided the chance to keep playing without the inherently increased risk of another concussion from a foul tip off his mask. (The A's are said to have also decided he wouldn't catch, but after signing DH Billy Butler, they didn't have an open spot for him.)"It's huge," Jaso said. "A blessing, really."Baseball operations president Matt Silverman said the Rays "spent a lot of time prior to the trade making sure his medicals passed our standards" and feel he is "fully" healthy (even cleared to catch), but acknowledge Jaso is at a somewhat higher risk overall."His concussion history affects his chances of injury," Silverman said. "Hopefully with the role we're asking him to play, he can stay healthy and be a productive player all year long."Jaso has been hitting and running around in the outfield with no issues, and he doesn't expect any."I feel great, I feel fine," he said. "As far as catching goes, if they were to say, 'Here, catch tomorrow,' I don't know. That's the scary part. Like I don't know if I could take one, take 40 foul tips, what it would be. … What I do know is that the longer I have between episodes, the stronger I'll be. It's letting the brain heal all the way again. You might think it's gone, you might think you are all right, but it's still there. You have to let it fully heal or else you can easily re-aggravate it."Jaso said the unknown of what a third concussion could mean to his career, and his life, has made him "a bit smarter" about how he handles himself, but that it won't alter how he plays."If I'm doing something, I'm doing it to the fullest," he said. "I'm not playing the game scared. When I'm hitting, I'm not thinking about getting plunked in the head or anything, I'm thinking about hitting the ball hard. …"Yeah, if I was to take another whack, a blow to the head, I am a little bit worried. But I don't carry it around with me." Contact Marc Topkin at email@example.com . Follow @TBTimes_Rays .