"I'm just waiting for that time, I'm ready to play" Severino said.
It finally came when Severino entered the game as a pinch-hitter for left-hander Matt Grace in the eighth inning. On a 1-1 pitch, Severino hit the ball to deep left field. Manager Matt Williams thought the ball was going out of the park, but it hit the fence for a double. Severino would later score on a single by Yunel Escobar.
How did Severino feel about what he accomplished?
"Oh, my God. Amazing," he said. "When I scored, everybody was in the dugout, I gave high fives. I'm proud of myself. I felt like I helped my team."
After getting his first hit, Severino said he plans to give the ball to his mother in the Dominican Republic.
"I dedicate that ball to her," he said.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He can also be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.