(CNN) -- Alex Torres will never forget the sound that echoed around Tropicana Field from the pitcher's mound on a Saturday afternoon last June.
More than a year after the pitcher's then-Tampa Bay Rays teammate Alex Cobb was struck in the head by a concussing line drive, that sound of ball on skull still resonates.
"I came in after Alex Cobb was hit in the head," Torres told CNN on Sunday. "That's really an impression to me, how his head sounded from the bullpen. That was really bad. I was shaking. 'Oh my God! Oh my God!' I'm glad he's alive."
Until Saturday, the most notable thing about Torres' brief 74-game Major League Baseball career was that the reliever, traded from Tampa Bay to the San Diego Padres over the past year, had struck out more than a batter per inning. But years from now, we might look back at the unheralded, undrafted pitcher as one of the game's pioneers.
When the 26-year-old Venezuelan strolled from the bullpen to the mound for the eighth inning of Saturday night's game against the Los Angeles Dodgers, he became the first pitcher to wear a protective cap that MLB approved in January for use by pitchers.
"It's a good idea they make this kind of hat to protect my head," Torres said. "You want to protect life. I don't have a kid yet, but I want to see my kid grow up."
4Licensing Corporation makes the new IsoBLOX Protective Caps, which its website describes as "breakthrough technology to protect Major League Baseball pitchers from line drive come-backers." The optional equipment was made available to pitchers at all levels during spring training, with interested players providing information so they could get fitted caps, MLB.com reported.
Line drives back to the mound have caused several injuries to pitchers over the past few years, some very serious. Most recently, the Cincinnati Reds' star closer Aroldis Chapman sat out the first six weeks of this season after a line drive in spring training caused fractures to his nose and above his left eye. In the most life-threatening incident, Arizona Diamondback Brandon McCarthy, then pitching for the Oakland A's, took a batted ball to the head in September 2012, then needed brain surgery because of internal bleeding.
The protective caps have padding imbedded inside the side and front. However, the portion of the head below the cap line, where MLB.com says many of the more seriously injured pitchers were struck, remains unprotected.
"The cap is fitted with uniquely-formulated protective plates that use a combination of dispersion and absorption techniques to diffuse energy upon impact with a high-velocity object," the IsoBLOX website says. "Under rigorous testing simulating MLB line drives, the isoBLOX® cap demonstrated protection at speeds up to 90 mph in the front and front boss impact locations and 85 mph on the side impact location."
Dan Halem, MLB's executive vice president for labor relations, and Patrick Houlihan, MLB senior counsel for labor relations, told ESPN in January that to get approval, the cap had to provide protection at 83 miles per hour, below the National Operating Committee on Standards for Athletic Equipment standard severity index of 1,200. Severity indexes higher than 1,200 are considered high-risk for skull fractures and traumatic brain injuries. An MLB-commissioned study determined that 83 mph was the average speed of a line drive when it reaches the area of the pitching mound, ESPN reported.
Player safety in sports has risen to the forefront in recent years, sparked by increased awareness of the repercussions of concussions and chronic traumatic encephalopathy, as well as high-profile player lawsuits against the National Football League.
All four major U.S. pro sports leagues -- MLB, the National Football League, the National Basketball Association and the National Hockey League -- have updated their concussion protocols in recent years.
Eighteen baseball players were placed on the disabled list after concussions in 2013. In 2012, 13 players were placed on the list after a concussion, and in 2011, the number was 11, according to MLB data.
The padding adds 7 ounces to the weight of a cap, which currently weighs 3 to 4 ounces, according to MLB.com.
Although the caps look bulky, "the difference between a regular hat [and the new one] is not a big difference. It's a little bigger than the regular one," Torres said.
Torres said the larger cap doesn't interfere with his pitching motion, and he practiced with the new cap on for three or four days over the past week before using it in the Dodgers game, to make sure it wouldn't bother him.
While a lot of Internet response has been supportive, many people online have been making fun of Torres' sartorial choice. The Padres' lefty said even a former teammate, Rays' star David Price, was tweaking him on social media. But he doesn't care, possessing the confidence to choose safety over style.
"It looks unusual. It isn't quite as formfitting and as chic as the baseball cap," the Padres announcers said during the telecast. "Obviously, the appearance has to change, because a lot of players these days, you can see, they want to look the part. They want to look really good, and that is not a good look."
While Torres doesn't think the protective caps should be mandatory for major leagues, he urges parents and children to consider them, because of a key difference between the majors and youth baseball.
"I think [children] should be using [the caps] because they use aluminum [bats], and the ball comes off the aluminum harder than the bat we are using," he said.