NEW YORK — The educated guess was that it was something he ate, but no matter the cause, Austin Hays had never dealt with anything like it before. “Once we found the infection and we were able to start treating it, it didn’t heal quite as quick as we would have liked,” the Phillies’ still-sort-of-new left fielder said Tuesday before  Game 3 of the National League Division Series against the Mets at Citi Field. “We went back, kept running the tests, kept trying to figure out what was going on.” What was going on was a kidney infection that wound up taking three weeks from Hays during September, as he was trying to earn a niche in both the Phillies’ clubhouse and lineup. What helped him out, in addition to the work of the club’s medical and training staffs, was the way the Phillies’ stretch drive ended. They clinched the National League East early, leaving Hays time to play several games at the end of the month. But that was just gravy on top of what was really important. “That was to see everything clear up,” he said, “and know 100% that it’s gone, and I’m healthy.” As for his status with the Phillies, however, that remains unclear. Currently on a one-year, $6.3 million deal, Hays is arbitration eligible next year and would be a free agent in 2026. Before looking ahead, however, he has to come to terms with the present. Hays had struck out in a pinch-hit appearance in Game 2 of the NLDS, but was in the starting lineup Tuesday for Game 3, and was scheduled to be in again Wednesday in Game 4, because the Mets were to start left-handers Sean Manaea and Jose Quintana. But with an oh-for-3 with two strikeouts through his first three at-bats Tuesday, it would seem at least possible that Hays has played himself out of that Game 4 start in favor of either righthanded Weston Wilson or recently struggling lefty regular Brandon Marsh. All of that remains to be seen, as do the Phillies’ immediate fortunes. “I told him at the start of the series that he’s going to start against left-hand pitching,” Phillies manager Rob Thomson said before Tuesday’s game. “But it was good to get him an at-bat (Sunday), get him in that environment. I think that it probably speeds up on a guy the first time you get an at-bat in that environment. Now as he’s had it, I think it will relax him moving forward.” Until this season, Hays seemed to be on a starring trajectory with an up-and-coming Baltimore team. An outfielder who could hit for average and power, he hit .309 with a .947 OPS during 21 games in 2019 while eventually graduating from the minors, but the pandemic slowed his rise. By 2021, however, he hit .256 with 22 home runs and a .769 OPS, then 16 homers each of the next two seasons, batting .250 and .275. This season, Hays found his playing time decreased. After playing 63 games with only three homers and 14 RBIs, he was traded to Philadelphia in late July for reliever Seranthony Dominguez and part-timer Cristian Pache. Hays hasn’t had a chance to live up to the billing as a platoon option who can offer pop off the bench. He missed two weeks in August due to a hamstring injury, then was hit with an infection that seemed to take too long for him to clear. Until he did. “I feel like I’m back to being myself,” said Hays, who in 22 Phils games hit .256 with two homers and six RBIs. “I don’t feel reserved in any way, in any facet of the game. My power is there, my strength is there, my speed. So I feel like myself all around.” It took a while, as Hays said he had setbacks along the way. But as far as his health is concerned, he’s getting better every day. He’s even had a chance to get a feel for postseason baseball in Philadelphia … for now. “Yeah, the Red October is real,” he said. “It was awesome.” Unfortunately for the Phils, awesome doesn’t always translate into playoff success.