In the third inning, on leadoff hitter Humberto Cota's drive to deep right-center field, Freel collided with right fielder Norris Hopper as the two converged to make the catch. Freel's head caught Hopper's right elbow before he fell hard on the warning track.
Although Hopper got up, Freel remained down and motionless on the warning track for several minutes and facing the fence on his side. Hopper tended to him immediately and said Freel was unconscious for a few moments.
"I screamed right in his ear, 'FREEL! FREEL! FREEL!' as loud as I could," Hopper said. "The first couple of times, he didn't even budge. But the fourth or fifth time, he kind of opened his eyes a little bit, but you could tell he didn't know what was going on."
Reds trainers, team medical director Dr. Tim Kremchek and Narron were among those who rushed out to see Freel.
"He said everything went black when [assistant trainer Steve Baumann] got out there," Narron said.
Freel, who is known for frequently giving up his body to make spectacular plays, was placed on a stretcher and into the ambulance with his head and neck immobilized as teammates looked on.
"You're worried and concerned," said catcher David Ross, who hit a two-run homer in Cincinnati's 4-0 win over Pittsburgh. "He's one of our best players. He's a spark for us. If he does well at the front of our lineup, we seem to click really good. In the outfield, he's irreplaceable."
The ball was found in Freel's glove by an umpire, who ruled Cota out on the play. Ken Griffey Jr. entered the game in Freel's place and played right field. Hopper was shifted to center field. It was not known how much time Freel would miss.
"That had the potential of being a real disaster," Pirates manager Jim Tracy said. "That was real close to being a vicious, vicious collision. When you have a right fielder and the ball is hit in the gap, and you know how hard that kid plays in center field, how hard he runs ... if they collide head-on, that's going to be not a good collision."