Astros outfielder Mauricio Dubon also left the game after replacing Alvarez.
ATLANTA, Georgia (KTRK) -- Yordan Alvarez was taken to an Atlanta-area hospital Friday night after he left the Astros game against the Braves due to illness.
The team announced that Alvarez, who started at left field for the opening game of Houston's World Series rematch, left due to feeling ill on the field at Truist Park.
The video above is from an All-Star break stream on the Astros' second-half chances.
"He was evaluated in the training room and then transported to a local hospital for further evaluation," the club tweeted.
After Houston's 6-2 loss, Astros manager Dusty Baker explained Alvarez experienced shortness of breath and pulled himself out due to it, adding his star's vital signs are normal and that he's feeling good. But an ER doctor evaluation would still be needed.
"He had shortness of breath. Then, when they shot the fireworks off, the smoke made it worse," Baker said.
Alvarez's departure was in the bottom of the fifth inning after he went to retrieve a Braves hit ball.
The 25-year-old then walked off the field and into the dugout while the next Braves batter was still at the plate, forcing the Astros to scramble for a replacement in left.
The situation took a strange turn when the Astros' head trainer went to the Braves dugout and called for their head athletic trainer and medical staff. All of them went to the Astros clubhouse.
The game broadcast didn't detect any one play that could have led to the reason Alvarez left.
Meanwhile, Chaz McCormick, who started in centerfield, moved over to left and Mauricio Dubon took center.
But Dubon's night was short-lived as well when he hit the wall hard in right-centerfield while trying to catch a fly ball in the sixth inning. He had to leave the game with an apparent shoulder injury and was replaced by Jake Meyers.
The Astros are outfielder-starved. Michael Brantley, who shared time in left with Alvarez, is out for the season. Utility man Aledmys Diaz is on the 10-day injured list with a groin injury.
Houston, who entered Friday's matchup 3.5 games ahead of the New York Yankees for the best American League record, have 41 games and nearly two months of the season left to play.