Nowinski said another sign that Gardner should have been immediately checked came from his postgame comments, when Gardner acknowledged he was stunned for a moment, but “once I got up I realized where I was,” adding that he recognized center fielder Aaron Hicks, who had come over to check on him.
M.L.B.’s concussion protocol lays out what trainers should look for when they are examining a player for signs of a concussion, including disorientation, loss of balance, and a vacant look. Trainers are also instructed to ask five questions: Which stadium are we in right now? What inning is it right now? Who scored last? Who did you play the last game? Did you win the last game?
The concussion protocol also warns that symptoms could still develop in the next 24 to 48 hours.
Since the beginning of 2013, 93 players have been placed on a disabled list with concussions, including six this season, according to M.L.B.
It is not clear if Gardner will be in the lineup on Friday — or at all this weekend. The Yankees, who were off on Thursday after they traveled home, will begin a series against the Boston Red Sox on Friday, with first place in the American League East at stake. Gardner often sits against left-handed pitchers, and the Red Sox are scheduled to start three left-handers.
Nevertheless, if there is a team that should be aware of the dangers of outfielders running into walls, it should be the Yankees. They have lost two outfielders because of concussions — Jacoby Ellsbury and Clint Frazier, each for at least a month — over the last 15 months, even though both were not immediately removed from the game.
“What surprises me is that is that we still aren’t conservative with athletes, especially in a sport like baseball when they have guaranteed contracts,” Nowinski said. “Teams are on the hook if they mismanage a concussion, so it’s worth jogging out to the outfield to check on him and have a conversation.”