CHICAGO -- Cardinals second baseman Kolten Wong exited the Cards' 7-4 loss to the Cubs on Tuesday -- Game 1 of a doubleheader at Wrigley Field -- after 6 1/2 innings due to a head contusion, and he later showed symptoms of having sustained a concussion. That kept him out of Game 2 and could possibly sideline Wong longer depending on the results of follow-up tests.

Wong, who has made defensive gems in three straight games, hit his head hard as he fell after making a leaping catch in shallow right field to end the fifth. He was slow to get up and felt dizzy while walking off the field alongside Cardinals assistant athletic trainer Chris Conroy. Wong remained in the game, struck out in a sixth-inning at-bat and played another half-inning in the field before being pulled as a headache intensified.

Video: [email protected]: Matheny discusses Wong's concussion

"I hit right on the side of my head and landed right on my face," Wong said. "It threw me back a little bit. I was a little dizzy. ... As the game progressed, my headache got worse and worse and so they brought me in. ... I had a headache the whole time, and it's still lingering a little bit."

The Cards put Wong through a series of exams to determine if he had sustained a concussion. Wong said afterward that he had passed the battery of tests, but manager Mike Matheny, speaking after Game 2, clarified that after further examination, doctors found signs of a concussion.

"We're going to have to watch this real close," said Matheny, whose playing career ended due to multiple concussions. "We'll take another look [on Wednesday] and have to be real careful with him."

Major League Baseball implemented a concussion protocol in 2011 that requires teams to submit player concussion tests to MLB's medical director, who then determines whether that player is cleared to return to the field. All players are given a baseline neuropsychological test during Spring Training that is used to compare results.

If it is determined that Wong will need multiple days off to recover, the Cardinals will have the option of placing the second baseman on the seven-day concussion DL.

Wong sustained the head trauma as he ranged out to right field on a short fly ball by catcher Miguel Montero with two outs and one on in the fifth inning of Game 1. With the wind gusting, Wong had to spin to make the catch as he fell.

"It was swirling all day, and it was one of those where the ball, I thought it was going to be on my right, and then it ended up taking a pretty good turn and I had to kind of make a maneuver and make that catch," Wong said.

Matt Carpenter replaced Wong at second base, marking the first time Carpenter has been back at the position since he started 128 games there in 2013. Carpenter started Game 2 at second, as well.

"You know how I stand on this issue," Matheny said. "We want to make sure we take as much as information as we can. We'll keep watching, see what the doctors and medical staff see."