Francisco Lindor and the Mets can breathe a sigh of relief. Imaging on Lindor’s injured lower back revealed “good news” on Monday, said the shortstop, who plans to return this regular season — and potentially this week. “Everything seems like it’s good,” Lindor said at Citi Field before the playoff-hopeful Mets began a three-game series against the Nationals. “It could be three to five days or it could be two to three. It depends how my back reacts. The training staff, they have an amazing game plan, and then it’s gonna be up to [Mets manager Carlos Mendoza] and if I feel OK to play.” Lindor, 30, did not know his specific diagnosis after undergoing an MRI, but he said he was still dealing with a bit of pain after exiting Friday and Sunday’s games early and sitting out of Saturday’s. “They just said it’s [my] back acting up,” Lindor said. “The medical term, I can’t tell you that. I listen to a certain point. As soon as they said ‘no structural damage,’ I tuned out. … It’s not a strain.” Lindor says he’s been dealing with the issue for around two weeks, but that a play at second base in Friday’s 11-3 win in Philadelphia put him “on high alert.” He left in the seventh inning of that game, then returned to the lineup Sunday, but he exited again in the second inning after feeling discomfort on his way to first base following a first-inning single. “I was expecting the worst, to be honest with you,” Mendoza said. “For Lindor to not be in the lineup one day, and then be in the lineup and come out of the game after one inning, that’s pretty telling, because I know how tough this guy is, and he’s gonna play through pain.” Lindor has been an ironman for the Mets, appearing in each of their games this season before Saturday’s and starting all but one of them at shortstop. Without Lindor on Monday, Mendoza gave second baseman Jose Iglesias his first start of the season at shortstop, batting out of the leadoff spot. Eddy Alvarez got the start at second base. The Mets remain without second baseman Jeff McNeil, who recently suffered a wrist fracture that’s expected to end his regular season. On Saturday, the Mets called up prized prospect Luisangel Acuna, whom Mendoza said will “get a pretty good chance” with Lindor out, most likely at shortstop. Lindor did not require any type of injection Monday but was prescribed medication to help him recover from an ailment he says has included tightness and soreness. Despite a slow start at the plate, Lindor emerged in recent months as a National League MVP candidate — a race that also includes Dodgers designated hitter Shohei Ohtani. Lindor’s 86 RBI and 27 stolen bases lead the Mets, while his 31 home runs rank second on the team. His .271 average and .836 OPS are the highest among the Mets’ qualified hitters. Now in his fourth year with the Mets, Lindor is also a clubhouse leader who called a players-only meeting after a May 29 loss dropped them a season-worst 11 games below .500. The Mets entered Monday 24 games above .500 since then and in a tie with the Braves for the third and final NL Wild Card spot. “I don’t want to be in this position, but I believe in my teammates,” Lindor said. “I believe in what they can do, and I’ll be their biggest cheerleader.”