An X-ray on Hayes' left shoulder came back negative. An MRI will be taken on Wednesday to see if there is any separation of structural damage.
Either way, Hayes will be out for a while. He said the range of motion in his arm right now is not good. The Marlins will make a roster move to add a catcher on Wednesday.
The fact that Morgan was involved in a controversial collision last Saturday with Bryan Anderson of the Cardinals had the Marlins taking issue with the Nationals outfielder.
"Obviously, his track record doesn't help himself," Hayes said. "Somebody who does that is looking to hurt somebody. But, you know, it's baseball."
Whether it was a clean play or overly aggressive, the collision raised the drama in a game dominated by pitching.
Morgan drew a walk off Clay Hensley in the 10th inning. With two on and one out, Adam Kennedy chopped a slow grounder to second. Emilio Bonifacio collected the ball and flipped to shortstop Hanley Ramirez for the force out at second. Ramirez wisely didn't throw to first, where he wouldn't have had a chance to double up Kennedy.
Morgan, who was on second, rounded third and charged home. Hayes retrieved Ramirez's throw, and before he could react, he was knocked down by Morgan.
Morgan went back to touch home plate as Hayes was on the ground, clutching the ball. Home plate umpire Jim Wolf signaled out, as Marlins players and coaches came onto the field to tend to the catcher. After a few minutes, Hayes walked to the training room.
"Hanley threw the ball in. It was a little high," Hayes said. "I caught it. I didn't have a chance to get my legs under me. It's baseball.
"I caught the ball. I peeked because and I knew he was coming home. I saw Hanley picked him up. It kind of caught him off guard a little bit. It was a high throw."
Morgan felt he needed to keep his footing and be aggressive.
"It was just one of those plays," Morgan said. "If I had slid, I probably would have hurt myself."
Realizing it would be a close play, Morgan added, "I know I had to kick it up a notch."
Marlins manager Edwin Rodriguez believed Morgan would have scored if he slid.
"If he would have slid at home plate, he would have been safe," Rodriguez said. "Hayes was more on the right side of the plate."
Asked if he felt Morgan made a clean play, Rodriguez said, "Then again, if the runner has his mind set already, that might have happened."
"Hindsight is 20/20," Nationals manager Jim Riggleman noted. "He made the decision and I don't have any problem with his decision."
Tracy, the Marlins third baseman, said seeing Hayes hurt energized the team.
"I would have said it was clean, if I hadn't seen what he had done earlier in the week in St. Louis," Tracy said. "That right there could have gone either way. I think he would have had a better chance, if he was sliding to be safe, than hitting the catcher.
"But I think he had made his mind up when he came around third that he was going to hit him. You can't really get upset right there, because anybody could have made the decision to hit him. The only thing that kind of fires you up is you've seen the way he's been playing the last week or so."