in conjunction with MLB and the union, and the bulky foam-padded isoBLOX cap. Alex Torres, who is no longer in the majors, wore the latter and received widespread attention. No MLB pitcher has worn the hybrid cap-helmet in a game.

The Kevlar-padded dome insert from Unequal Technologies was worn in 2015 by two big league pitchers who are no longer in MLB, and Shoemaker said he seriously considered using the BCL ball cap liner of carbon fiber and foam produced by former major leaguer Cliff Floyd and his father-in-law.

Contacted Friday by OTL, Matt Meier, the founder and CEO of SST, said he has reviewed the video from the plays involving Shoemaker, Ray and two pitchers who were struck in the months between those instances. Regarding Ray, Meier said, "Itdefinitely hit him in a position that it [the SST guard] would've helped him. Thankfully, he was able to avoid major injury." Meier added that he thinks his company's insert would have lessened the impact in all four cases.

The other two were Blue Jays Triple-A pitcher T.J. House, who was hit in the head in a spring training game with Toronto's major league team, and Cardinals Triple-A pitcher Daniel Poncedeleon. House, whose incident was March 10, escaped serious injury. Poncedeleon, however, has been out of action since a May 9 liner struck him in the temple; he required emergency surgery to relieve swelling of the brain and was hospitalized for two weeks.

The SST guards, according to Meier, have been designed to reduce the risks of skull fractures and