Daniel Robertson turned in the biggest hit of his career Sunday afternoon, a walk-off grand slam for his Tampa Bay Rays, and then delivered something even bigger.

The 24-year-old shortstop celebrated with teammates, met with reporters, showered, changed and made a beeline out of the ballpark. Barely 90 minutes later, he was riding an elevator to the seventh floor of Johns Hopkins All Children’s Hospital in St. Petersburg, Fla., where 15-year-old Joey Johnston was lying in a bed, just as he had been for the past two weeks.

Johnston was wide-eyed — and in a bit of shock. “Joey just stared at him, like, ‘Uh, we just saw you hit a grand slam to beat the Marlins,’ ” the boy’s father said.

Joey, a baseball player himself, was beaming. He’d broken multiple bones in his neck and back two weeks earlier in an accident and had been confined to a bed since. He is not one for grim prognoses, but doctors aren’t sure if or when he might walk again.

“I did that for you, bud,” Robertson told him.

“Just to see the excitement and joy on his face when I walked in that room, it’s honestly something I’ll never forget,” Robertson explained in a telephone interview Monday with The Washington Post. “It was a pretty special moment.”

Daniel Robertson visits 15-year-old Joey Johnston in the hospital after hitting a walk-off grand slam. (Courtesy of Joey Johnston)

The hospital visit was a welcomed pick-me-up for a family still sorting out how youthful indiscretion could upend normalcy so brazenly, how an energetic and active teenage could suddenly be rendered motionless, encased in tubes and fastened into a halo traction that stabilized his fragile neck and spine.

“It was and is surreal,” said his father, who is also named Joey Johnston. “He’s never sat still this long in his life, truly.”

On July 8, the teenager, a lifelong Rays fan, jumped from a bridge into water. The disastrous landing could have been fatal had a friend not swam Joey to safety. He was rushed to the hospital and has since undergone two surgeries to fuse together his fractured vertebrae with screws and rods.

Word of the accident spread quickly. Joey was outgoing and quick to make friends, and his father is a longtime, well-regarded sportswriter in Tampa Bay. Tony Dungy and Jon Gruden both called for updates. A trio of Rays players — Robertson, Chris Archer and Kevin Kiermaier — sent a get-well video, and the following day, Dave Haller, the team’s director of communications, stopped by the hospital with a goody bag, including a jersey signed by all the players.

Robertson wanted to do more, though. Johnston had interviewed Robertson just a few weeks earlier, and the sportswriter had regaled the ballplayer with stories about his son, who had just completed his freshmen season playing for the varsity team at Alonso High in Tampa.

“Something kind of just laid on my heart Sunday morning,” Robertson said. “I woke up and immediately when I got the field, I told Dave, our PR director, that I really wanted to go see Joey. I felt pulled, like it was something I needed to do.”

Haller called Joey’s father and asked for the room number. Not wanting to get his son’s hopes up prematurely, Johnston didn’t mention it to his son.

Robertson had been mired in a slump of sorts with only three hits in his previous 26 at-bats. He had the day off. At the hospital, the Johnstons had the game on the television and watched bits and pieces as visitors came through to check on Joey.

The Rays trailed 4-1 entering the bottom of the ninth. They put one across the plate and suddenly had two runners on with two outs. The cameras showed Robertson in the on-deck circle, and Johnston chuckled to himself. The veteran sportswriter knew the sports world has a funny way of delivering magical stories.

“I knew exactly what was going to happen,” he said. “I had no doubt that he was going to come up with the bases loaded and he was going to hit a grand slam. I would’ve bet everything I own.”

The Marlins indeed walked the next batter to load the bases, and Robertson strolled to the plate, facing a 4-2 deficit and carrying with him that week-long slump.

“Something was different. I felt totally ready,” Robertson said. “I went into the cage Sunday morning and something clicked. I was hitting in the cage all game, and things felt right.”

The first pitch was a ball. The second was crushed over the left field wall for Robertson’s eighth homer of the year. It was the first walk-off grand slam in Rays history.

In the seventh-floor hospital room, Johnston just laughed as Joey and his friends celebrated the Rays’ dramatic win. As Robertson went through his postgame obligations, Joey’s family and friends were soon sent down in the lobby while the teenager met with nurses. That’s when Johnston spotted Robertson and escorted the Rays player to his son’s room.

“I said, ‘I appreciate you coming, but you didn’t have to do it this big,’” Johnston said. “This is like Babe Ruth stuff.”

“Clearly it was like the biggest homer of the guy’s professional life, and there were any number of things he could’ve done,” Johnston continued. “But as soon as he could, he was right there to check in on Joey. That meant a whole lot. That’ll continue to mean a whole lot. Just seeing the smile on Joey’s face after what he’s gone through, it means everything.”

Robertson brought along some batting gloves as gifts and chatted with Joey. He told him about adversity he has had to overcome in his own life — Robertson’s father died in 2013 from cancer — and told Joey to keep fighting.

“Being a professional athlete, it’s just the platform we’re on,” Robertson explained later. “Getting to do things like that. I don’t know — something touched my heart, man.”

For an encore, Robertson homered again Monday night, a sixth-inning shot to right-center against the Yankees. As he crossed the plate, he pointed to a bracelet he was wearing on his left wrist in Joey’s honor.

The family is hoping Joey will be released to a specialized rehabilitation facility this week. They have started a GoFundMe page to help cover hospital costs. And while they don’t know what the future holds, they know what kind of fighter their son is. He doesn’t simply want to walk again. Joey has his sights set on returning to the baseball field.

Until then, he will continue watching the Rays. He will be inspired by Robertson’s graciousness, and for his part, Robertson says he will be encouraged by Joey’s positive outlook.

“Honestly, the satisfaction of going to the hospital and touching that family’s lives was definitely more special than hitting a walk-off grand slam,” Robertson said. “I know that might be hard for some people to understand, but baseball comes and goes, man. The lives we can touch and make an impact on while we’re playing this game means way more than any on-field accomplishment. So it was pretty cool.”

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