CHICAGO -- Cubs manager David Ross took no chances when outfielder Jason Heyward complained of shortness of breath and light-headedness during Sunday's game against the Cardinals. And by Monday morning, Ross was encouraged by the feedback from Heyward and the team's medical staff about the veteran's recovery from the episode.

"I talked to him last night and this morning. He seems to be feeling much better," Ross said prior to Monday's game against the Cardinals. "Lots of tests run last night at the hospital pretty late. He'll have the day off today."

Ross noted that Heyward will go through additional tests Tuesday, when the Cubs welcome the Reds to Wrigley Field for a three-game series. The manager declined to address the specific nature of Heyward's condition, but the manager expressed in general that the Cubs have not had any positive COVID-19 tests to date.

"I can tell you that," Ross said.

Heyward was pulled after four innings in the 7-3 loss on Sunday night and was sent to a local hospital for further evaluation, but Ross noted that the outfielder did not need to stay overnight for observation.

"He said he felt a little light-headed after the first at-bat," Ross said after Sunday's game. "He's not a guy that you ever have concerns about, so when he says he is having trouble breathing and is light-headed, I just wanted to make sure everything's all right."

Heyward grounded out in the second inning, struck out in the fourth and manned right field for four innings before being replaced by Cameron Maybin.

Through 35 games this season, Heyward has been an offensive leader for the Cubs, batting .300/.415/.540 with five homers, five doubles, two triples and 17 RBIs. He also had as many walks (20) as strikeouts (20) in what has been a career-best pace across the board.

Beyond his work on the field, Heyward has also continued to be an unquestioned leader behind the scenes for the Cubs.

"He's kind of the steady rock, always," Cubs second baseman Jason Kipnis said Sunday. "He just stays the course -- kind of like a, 'Follow me.' Every day, he shows up -- same guy whether he's hitting or not hitting. He works hard. So when you're around him, you're working a little bit harder, because you know he is, too. He's just one of those guys that kind of brings people along with him.

"We're hoping it's not serious with what he's got going on."