New York Mets manager Terry Collins stands in the dugout before a baseball game against the Pittsburgh Pirates in Pittsburgh, Tuesday, June 7, 2016. The Pirates won the first game of a double header, 3-1. (AP Photo/Gene J. Puskar)
New York Mets manager Terry Collins stands in the dugout before a baseball game against the Pittsburgh Pirates in Pittsburgh, Tuesday, June 7, 2016. The Pirates won the first game of a double header, 3-1. (AP Photo/Gene J. Puskar) Credit: ap file — Gene J. Puskar

Milwaukee — New York Mets manager Terry Collins will remain overnight at a local hospital for observation and more tests after falling ill about 30 minutes before Sunday’s 5-3 loss to the Milwaukee Brewers.

When asked about his level of concern, assistant general manager John Ricco said, “I don’t think it’s high.” The team did not disclose Collins’ precise symptoms.

The team traveled back to New York for a scheduled day off today while Collins stayed behind in Milwaukee, along with team trainer Ray Ramirez.

“They were watching the game, I know that,” Ricco said after the Mets’ sloppy loss. “He’s probably a bit agitated, knowing Terry. But other than that, he’s feeling fine.”

It’s unclear whether Collins will manage the Mets’ next game Tuesday night against the Pirates.

Collins, 67, is the oldest manager in the big leagues. He had not complained of any issues earlier in the day and his illness caught team personnel by surprise.

Before managing the game, bench coach Dick Scott called a brief team meeting in the clubhouse about 30 minutes before first pitch to announce that Collins had left the team.

By then, the manager had complained of feeling ill and was seen by medical personnel at Miller Park. He then showered and walked out of the Mets’ clubhouse under his own power, headed for nearby Froedtert Hospital.

“I was just with Terry,” Ricco said just before the game began. “He was alert and fine. Just wasn’t feeling well before the game, so we’re going to have some tests run. … We’re just being cautious.”

Curtis Granderson said that aside from Scott’s announcement, players received little information about Collins’ condition. He insisted it did not impact the team’s play, but Scott acknowledged that it might have been a factor in the Mets’ uncharacteristically sloppy loss.

“First and foremost,” Scott said, “all of our concerns are with Terry right now.”