A broad outcry after a small girl was hit in the head by a foul ball at Yankee Stadium two years ago spurred Major League Baseball to do something it had repeatedly resisted: It compelled all 30 teams to extend protective netting to the far end of dugouts.

The question, raised again after another episode on Wednesday night in which a young girl was injured by a line drive in Houston, is whether M.L.B. has gone far enough to keep fans safe.

In Wednesday’s game, a scene eerily reminiscent of the one in the Bronx was repeated: Another small girl was cradled in the arms of a man as he hustled up the stadium steps to seek medical attention for her. The players who witnessed the episode were visibly shaken.

The girl was injured in the third inning, when a line drive off the bat of Chicago Cubs center fielder Albert Almora Jr. whistled into the seats in Section 111, just past the visitors dugout down the left-field line where there is no protective netting.

Almost immediately, Almora put his hands on his helmet and Houston Astros catcher Robinson Chirinos turned his head away. Almora took several steps toward his dugout, then dropped to his knees. He had to be consoled by Manager Joe Maddon and his teammate Jason Heyward as the girl, who had a yellow bow in her hair and was crying, was carried away for treatment.

After a brief delay, the game resumed. An inning later, Almora was in tears when he talked to a security guard near Section 111, embracing her before being led by his teammates back into the dugout. The Astros said in a statement that the girl had been taken to the hospital, but they announced nothing about her condition.

“As soon as I hit it, the first person I locked eyes on was her,” Almora, who has two young boys, told reporters after the game. He added: “Right now, I’m just praying and I’m speechless. I’m at a loss for words.”

The episode brought renewed anguish for Geoffrey Jacobson. It was his daughter, weeks shy of her second birthday, who was hospitalized with multiple facial fractures and bleeding on the brain after being hit by a foul ball at Yankee Stadium on Sept. 17, 2017.

For more than 100 years, a disclaimer has been printed on the back of every Major League Baseball ticket warning of the “risk and danger inherent to the game” and the possibility of injury from, among other things, “thrown or batted balls.”

But the game and the viewing conditions have changed greatly in a century. Bulked-up pitchers and hitters are throwing and swinging harder than ever, and seating is now closer to the action, with fans having many more sources of distraction, like smartphones, as they watch. Last season, for the first time, all major league stadiums agreed to extend protective netting to the far end of each dugout.

Even so, many foul balls can still reach the stands at speeds exceeding 100 miles per hour and cause injury or death. Last August at Dodger Stadium, Linda Goldbloom, 79, was sitting in a second-deck seat behind home plate when a foul ball cleared the netting and struck her in the head. She died four days later.

“It was a straight shot,” Goldbloom’s daughter, Jana Brody, told The New York Times in February, adding later, “Yes, the netting got widened, but it didn’t go vertical, and that would have been a huge change for my mom if it went up, too.”

Brody told ESPN on Thursday that it was “unconscionable” that M.L.B. had not extended the netting further since her mother’s death.

Major League Baseball said in a statement: “Clubs have significantly expanded netting and their inventory of protected seats in recent years. With last night’s event in mind, we will continue our efforts on this important issue.”

While a number of teams, including the Yankees, had resisted extending protective netting, citing complaints from fans who said it detracted from the experience of sitting in the more expensive seats, the Astros were among the first to extend netting on their own, before the 2017 season.

The team’s president, Reid Ryan, said in an interview during the 2017 playoffs that the Astros had visited other ballparks that had extended netting the previous season — in Minnesota, Kansas City, Washington and Texas — to measure distances from home plate to the stands and look at different types of netting to determine the best ways to keep fans safe while not detracting from their experience. The Astros constructed 12-foot-high netting that extended along both dugouts to go with the 32-foot net that already existed behind home plate.

But Andy Zlotnick, who has advocated extending protective netting since he sustained permanent eye damage after being hit by a foul ball at Yankee Stadium eight years ago, said that Wednesday’s episode was proof that baseball’s standards are inadequate. He said the current standards for protective netting would not have prevented his injury.

“For years we’ve been saying, ‘What will it take, a fan to die?’” Zlotnick said. “And then a fan dies, and what does the owner do? What does Major League Baseball do? Nothing.”