DENVER -- Major League Baseball's approval of a protective insert that pitchers can wear to protect against line drives to the skull brought back memories of a frightening incident on Aug. 5, 2011. Rockies right-hander Juan Nicasio suffered a fractured skull and broken neck when hit by a line drive from the Nationals' Ian Desmond.

Rockies head athletic trainer Keith Dugger has tested several potential protective devices and is a proponent, but he said the decision whether to wear it is up to Nicasio and any other player. The use of such a cap -- it was announced Tuesday that one manufactured by the 4Licensing Corporation subsidiary isoBox was approved by MLB -- is optional.

"We'll bring it to his attention," Dugger said. "We'll fit one on him and ask him to test it again, and see if it's something he wants to go with.

"It's a good thing. It's one of the few devices that has passed standards and it can be custom fit for anyone. It's just going to take time to get used to. The good thing is there are options for players."

Dugger said Nicasio has tested several proposed protective caps, including the isoBox, in Spring Training bullpen sessions and hasn't found one he likes, but he will offer Nicasio the opportunity to wear it.

The optional headgear can be worn by any defensive player other than the catcher, who is required to wear a helmet, Dugger said.

"Anyone who has had an experience with an injury, such as Juan Nicasio or Justin Morneau [newly signed first baseman with a concussion history], we'll suggest it and show it to them," Dugger said. "We can never mandate it. What we'll do is suggest it and let the players know what's out there."

The padded cap faces obstacles to its acceptance.

The cap adds 7 ounces to the normal cap weight of 3-4 ounces, and it adds slightly more than a half-inch to the front of the cap and an inch to the sides, so getting used to the feel of the cap is an issue.

Nicasio isn't the only pitcher hit by a line drive to be concerned about the feel of protective headgear.

"I'd have to see what the differences in feel would be -- does it feel close enough to a regular cap?" Blue Jays pitcher J.A. Happ, who suffered a fractured skull last May 7, told ESPN. "You don't want to be out there thinking about it and have it take away from your focus on what you're doing."

Like advances in batting helmets that are bigger than and look different from previous models, the padded cap is up against the fashion sense of players. The distributed photo of the cap resting on a mannequin received a thumbs-down from Rockies left-hander Brett Anderson.

"I'll pass on the Super Mario Brothers inspired padded hat," Anderson tweeted Tuesday.

While the padding follows the inner shape of the cap, many of the line drives that have injured pitchers have hit lower on the head. Nicasio was hit on the temple near the orbital bone. Dugger, however, said the padding can be modified to protect the temple or other areas of concern.

Dugger noted that no device prevents all injuries. But he compared it to the incident when Rockies Double-A first-base coach Mike Coolbaugh was killed when hit in the neck by a line drive on July 22, 2007. Then-Rockies first-base coach Glenallen Hill, now manager of the Rockies' Triple-A affiliate in Colorado Springs, pioneered the use of a skully helmet (a helmet without earflaps). After that season, Major League Baseball mandated that first- and third-base coaches wear the helmet to protect their heads.

Whether the cap gains initial acceptance could depend partly on who chooses to use it. Eventually, Dugger sees it being mandated in amateur ball, so players will be used to it by the time they enter pro ball. That's been the case with the hockey goalie-style catcher's helmet-mask combo. High school rules dictate that the catcher's ears must be covered, so they are used to the combo mask. Some catchers go with the skully helmet and separate mask when they go pro, but many stay with the combo.

"Nobody wanted to wear a helmet when they went skiing, but now it's a mainstay," Dugger said. "It may take a star player wearing it and making it a new trend. Then the kids catch on to it and so do the parents."