But little by little, he regained the wind that had been knocked out of him. He was helped to his feet, and he finished the inning.
And in the bottom of the inning, while the trainers tried to convince him to come out for a pinch-hitter, Beltran regained enough motion in his left knee to stay in the game and shoot a single into left field.
"It's a little bruised, but yeah, I am most concerned about my knee. It hurts," Beltran said. "I expect to come out and do everything I can do to play [on Tuesday against the Cubs], because we are in a situation where we have to play."
Beltran finished the game, batting in the ninth inning as well, hitting a groundout that scored David Wright to reduce the Cubs' lead to four runs.
Looking back at the play, Beltran said that the wall came up faster than he expected, and he immediately grabbed the left side of his rib cage after his left elbow was crushed into his side.
And though he expects to play on Tuesday, he's going to wait to see how the swelling in his left knee looks a day after the collision.
What is certain, however, is that he wants to be on the field for the rest of the season.
"Hopefully, tomorrow I can wake up feeling -- I am going to feel sore -- but hopefully good to play," he said.
Jon Blau is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.