It's become frightfully familiar.
A major leaguer fires a pitch from the mound, and seconds later everyone in the ballpark fears for his future. In just under two years, seven MLB pitchers have been hit in the head by line drives.
The latest episode was Thursday night in Pittsburgh when the Marlins' Dan Jennings suffered a concussion and was hospitalized after Jordy Mercer's liner struck the 27-year-old lefty in the head. The speed of the ball off Mercer's bat was reported as 101 mph.
On Friday, MLB and MLB Players Association officials told "Outside the Lines" they have been engaged for months in an unannounced jointly funded initiative with Boombang, a California-based engineering, research and consulting company, in an effort to advance the development of protective headgear for pitchers.
"Our hopes are that they come up with something that pitchers can use without interfering with their mechanics," MLBPA assistant general counsel Bob Lenaghan said.
Brandon McCarthy, Mickey Storey, Doug Fister, J.A. Happ, Alex Cobb and Aroldis Chapman were the six earlier victims of line drives to the head -- only Fister was able to stay in the game.
The Rays' Cobb, who suffered a concussion when he was struck in the head last year, told "Outside the Lines" on Friday that seeing the video of Jennings' injury "brought all the memories back. It makes you feel heavy in your stomach.
"I was really happy to see him conscious and walking and to find out his CT scan results showed he was OK."
In the months after McCarthy's life-threatening episode on Sept. 5, 2012 -- he required brain surgery after Erick Aybar's liner struck him -- MLB said its efforts to develop protective headgear for pitchers took on new urgency.
Until now, one padded headgear product has received approval for use by MLB pitchers, but the added weight and width of the isoBLOX cap and its bulkier appearance have been obstacles to widespread use.
One pitcher in the majors, the Padres' Alex Torres, and one in the minors, Marlins Class A righty Ramon del Orbe, have worn the isoBLOX cap in regular-season action, according to Mark Panko, president of 4Licensing Corp., whose subsidiary Pinwrest is the manufacturer.
Elliot Kaye, chairman of the U.S. Consumer Product Safety Commission, told "Outside the Lines" through a spokesman that Torres is a "major league hero" for wearing the padded cap.
But Kaye, who joined MLB at a news conference before last month's All-Star Game to raise awareness of head safety issues among children, said, "protecting one's head and protecting one's brain are not the same.
"We are aware of no product that has been proven to specifically reduce the risk of concussions and other serious brain injuries in sports."
The use of any protective headgear by an MLB pitcher is permissible, as long as it doesn't interfere with competition. Mariners pitcher Chris Young, who was with the Padres when he was hit between the eyes and severely injured by a 2008 Albert Pujols line drive, has told "Outside the Lines" he thinks padded caps should be considered just a start and perhaps visors such as those worn in hockey could eventually be the best option.
MLB officials have told "Outside the Lines" that no headgear with coverage beyond what caps provide has been considered for approval. But Young and others have been injured when struck beneath the cap line.
Even the official Rawlings MLB batting helmets aren't touted as fail-safe protection against balls traveling above 100 mph. When the isoBLOX cap was approved in January, MLB said it met a safety standard at 83 mph -- which was determined to be the average speed of liners reaching the mound.
Panko said about 70 MLB pitchers -- including a few who have been hit by liners -- have received custom-fitted isoBLOX caps to review and test. The caps, according to Panko, add close to six ounces to a standard 4.6-ounce official MLB New Era cap, and the width increase from the approximately one-quarter of an inch standard ranges from half-an-inch in the front to three-quarters of an inch on the sides, which he said are the critical regions for protection.
Cobb is now an endorser for the isoBLOX product being marketed to youth league and softball players, but his disinclination to wear its MLB product on the mound illustrates the current gap between approval and acceptance.
"I haven't had the courage to make a huge adjustment and introduce something new," said Cobb, who added that he didn't receive the padded cap until late in the spring and that the isoBLOX product for MLB pitchers is significantly "more cumbersome" than what's used for children because of the need for protection at far greater speeds.
"We're doing everything we can to refine the cap to where pitchers feel comfortable with it and it's not a distraction," Panko said. "Obviously, widespread adoption is our long-term goal."
As for the new MLB/MLBPA project with Boombang, MLB executive vice president Dan Halem said he hopes to receive substantive recommendations in the offseason that could soon generate new products from manufacturers for consideration.
When asked his reaction to the new MLB/MLBPA effort, Cobb said, "It proves that everybody is putting their differences aside to make real progress together."
MLB and the players' association previously worked with Boombang to devise measures such as a "wrap" to improve the safety of maple bats.
Many acknowledge that for protective headgear among pitchers to become a common sight, it will take improved products and early delivery of an important message.
According to Kaye, "The answer at this time is to build upon the progress made in recent years to significantly accelerate culture change around brain safety in youth sports."