Eric Hartline-USA TODAY Sports

Aaron Barrett planned nothing. The moment he found himself standing outside the Nationals’ dugout, in a battle of hand-over-heart attrition with the Rockies’ Brandon Barnes, surprised him as much as it did anyone else at Coors Field.

“If you would have told me this morning that I would be doing that,” Barrett said, “I would have laughed.”

Before the Nationals lost to the Rockies, 6-4, Barrett engaged in an organic, pregame standoff/staredown with Barnes, the pinch hitter he struck out in a key spot Monday night. Following the national anthem, Barrett and Barnes remained outside their respective dugouts, hats off, challenging one another to see who could hold out the longest. Barrett won after home plate umpire Paul Emmel threatened Barnes with an ejection.

“It was pretty funny,” Barrett said. “I’m not going to lie. Baseball is supposed to be fun. It was pretty fun to be a part of that.”

The contest materialized after the national anthem. Barrett was standing next to fellow reliever Jerry Blevins. A group had carried an American flag on the field, and Blevins told Barrett, “We’re staying out here until the flag goes out.”

They noticed across the field that Rockies closer LaTroy Hawkins had stayed on the field, too, telling a rookie to stay with him until the flag left. Barnes stayed, too. Hawkins and the rookie left once the flag was carried out. Barnes didn’t.

“Stay out there,” Blevins told Barrett.

Barrett and Barnes nodded at one another, and it was on. Barnes’s teammates poured cooling water over his head and fed him sunflower seeds. Hitting coach Rich Schu poured water down Barrett’s throat. Blevins applied sunscreen on Barrett’s neck. First base coach Tony Tarasco yelled a pep talk at him. Blevins gave him an oxygen mask. Teammates yelled from the dugout, “You better stay out there!” Barrett told himself he had to.

“Otherwise,” Barrett said, “they’re going to give me more [trouble].”

After several minutes, Coors Field showed Barrett and Barnes on a split screen on the video board. Jorge De La Rosa neared the end of his warmup pitches, and leadoff hitter Denard Span walked from the on-deck circle. Someone placed a helmet on Barrett’s head. Bryce Harper wrapped an elbow pad around Barrett’s arm.

“The umpire looked at me and was like, ‘If there’s a pitch and you’re still there, you’re gone,’ ” Barnes told the Denver Post.

Barnes tried to challenge to Barrett to a game of Rock, Paper, Scissors, and Barrett refused. To avoid the most ridiculous ejection in baseball history, Barnes turned and headed into the dugout. Barrett, who had been standing closer to the railing, raised his hands and claimed victory.

“It was a big win for the team,” Barrett said. “They were getting pretty serious behind me. He wanted to do Rock, Paper, Scissors for the end. The guys were like, ‘You better not lose.’ I didn’t want to hear the wrath of the team if I would have lost. Why not? It was fun. It was good camaraderie.”

Alas, Barrett’s performance in the actual game did not match his performance before it. In the seventh inning, Barrett allowed two runs, one of them unearned, as the Rockies made the score 6-2.

“I wish I would have done a little bit better and we could have got a win,” Barrett said. “It would have been two wins for the day.”