CHICAGO -- Nasim Nuñez has seen limited playing time in the first six weeks of his Major League career, but that has only emphasized the importance of staying prepared for the 23-year-old rookie infielder.

When his number was called in Game 1 of the Nationals’ doubleheader against the White Sox on Tuesday at Guaranteed Rate Field, Nuñez was ready. In Washington’s 6-3 win, Nuñez pinch-ran and scored the go-ahead run in the eighth inning, sparking a Nats rally with great baserunning.

Washington split the twin bill, dropping the nightcap, 4-0.

The Nationals selected Nuñez in the Rule 5 Draft this past offseason, and he made their Opening Day roster this spring. But entering Tuesday, he had only appeared in nine of Washington’s 39 games and received just three plate appearances.

“A lot of the coaches and teammates, they help me,” Nuñez said. “They mentally help me, let me know certain situations, and as I'm sitting there watching the game, I kind of start reading the situations.”

Nuñez pinch-ran for Joey Meneses, who singled to lead off the eighth, when the score was tied at 3. He was attempting to steal second base when Luis García Jr. grounded out to third baseman Zach Remillard on a ball that pulled Remillard closer to the shortstop hole.

Nuñez recognized this and quickly turned on the jets. He advanced to third, where he slid in safely with a dive to beat first baseman Andrew Vaughn’s throw across the diamond.

“Honestly, I didn't even think I was going to make it to second because the pitcher [John Brebbia] was pretty quick,” Nuñez said. “But they told me I should go, and it was a perfect situation. When I got to second, I looked up and the third baseman was kind of lackadaisical. He was a little slow. So [the] opportunity just presented itself.”

Adding to his dash from first to third, Nuñez’s helmet came off as he pulled into second base. He said he has a “little bit” of experience playing running back from a time before his Major League career, which showed as he cradled his helmet like a football for a few moments as he ran before tossing it aside.

“I don't remember, honestly,” Nuñez said with a laugh when asked about what happened with his helmet. “I just know it wasn't on my head when I was going to third, and I was hoping I didn't get hit in the head with the ball.”

It didn’t appear to slow him down any. According to Statcast, Nuñez’s sprint speed on the dash was 30.5 feet per second. For reference, Kansas City’s Bobby Witt Jr. entered Tuesday first in MLB this season with an average of 30.4 feet per second.

“It’s a split second to decide whether I can make it with my speed versus [Remillard’s] speed, so I chose mine,” Nuñez said.

The Nationals went on to score three times in the inning. After Nick Senzel walked, Nuñez scored the go-ahead run on Keibert Ruiz’s pinch-hit single. Then Trey Lipscomb’s single drove in Senzel, and Ruiz scored on a Victor Robles sacrifice fly. The late-inning rally backed a solid start from Trevor Williams, who was charged with three runs (one earned) over five innings.

“Great baserunning right there,” manager Dave Martinez said. “I figured we got one shot to get [Nuñez] in there and try to get something going. He did a great job getting to third base.”

Sticking to the theme of being ready when your number is called, rookie lefty Mitchell Parker continued his impressive first stint in the Major Leagues with a solid outing in Game 2. He allowed three runs and five hits in five-plus innings, with two walks and three strikeouts.

The damage came on one swing in the third, when Parker gave up a three-run homer to Andrew Vaughn on an 84.9 mph splitter just below the knees.

“It was a good pitch,” Parker said. “Good pitch, good hitter. A little disappointing because it was a good one, felt good, but it's going to happen. Just got to move on.”

Parker exited with the bases loaded and no outs in the sixth, but Jordan Weems got out of the jam unscathed on three pitches thanks to a 1-2-3 double play and flyout.

Parker, the Nationals’ No. 20 prospect according to MLB Pipeline, joined the rotation last month in place of the injured Josiah Gray. In six starts, he has a 3.09 ERA over 32 innings.

“When you can leave the game just giving up three runs, it gives us a chance to win games,” Martinez said of Parker. “He did well.”