HOUSTON — Considering the already slim odds of a slow-to-grow boy from Arkansas making the major leagues, a coin flip doesn't sound so bad. The doctor who performed major surgery on Ashur Tolliver's labrum four years ago wouldn't even give him that.

“He basically said you've got less than a coin flip — that's your chances,” Tolliver said. “That's your chance not to come back stronger, but just to come back to where you were.”

Less than a coin flip.

So what happened in an otherwise forgettable game for the Orioles on Thursday night was never guaranteed, and only recently even became a realistic hope.

Tolliver struck out three Houston Astros in 11/3 innings, making his major league debut in front of the family members who spent so many years convincing themselves this day would come that it still sounded like they were willing themselves to believe it as they sat in the ballpark waiting for it to happen.

“It's pretty special,” Tolliver said. “I don't think I ever lost hope, but there were times when it was so far away.”

It was furthest after the surgery four springs ago, but this wasn't a sure-fire major league career that had been interrupted.

An observer at his first high school baseball tryout asked the coach at Sylvan Hills High in Sherwood, Ark., why he was letting a kid shag balls.

The kid was Tolliver, and he didn't look like much but he could pitch. His path from there wasn't glorious — two colleges (Arkansas-Little Rock and Oklahoma City University), then a contract with the Orioles as a fifth-round draft pick in 2009.

He moved slowly through the organization, pitching well enough but not excelling, when in the spring of 2012 Tolliver just couldn't recover in between outings. The shoulder is not the elbow, with Tommy John reconstruction making repairing injuries to the latter “an art,” as Tolliver calls it. Shoulder surgery is complicated, and a last resort. Not for him.

“They never really suggested rehab, which made me know it had to have been pretty bad,” Tolliver said. “Normally, you don't go just right into surgery if you don't have to. You like to rehab it and see if you regain that strength and build those muscles up. That was never really encouraged, so I knew it must have been pretty substantial.”

Along with the coin-flip comment, the doctor also had something of a challenge.

“They said there's only so much they can do,” Tolliver said. “They can fix you. The rest is on you.”

As he worked his way back, he had time to finish his degree in occupational therapy, something that came up in phone calls back home to his father when his shoulder seemed as if it wasn't recovering.

“He called a few times and said, ‘I really need to look into that occupational therapy thing,'?” Gregg Tolliver said. “?‘It's not working for me.' But he hung in there.”

“Coming back from labrum surgery, stuff wasn't there, the velocity is not there,” Ashur Tolliver said. “It seemed like such a long shot.”

Tolliver's rehab in 2012 in Sarasota, Fla., coincided with Alan Mills' first year coaching in the organization. Now the pitching coach at Double-A Bowie (it was Mills who told Tolliver he was promoted earlier this week), Mills had come back from two shoulder surgeries in his own career.

He understood what Tolliver was going through and encouraged him to push through.

“You never know when you're going to bounce back,” Mills said. “You always have that doubt, that fear that it's not going to be able to come back. It's always great to get a call-up to the big leagues, but all the things that he's been through, the adversity and the obstacles and all of that, to make it to this point is just sheer joy.”

Tolliver had other minor injuries along the way — hamstring pulls, a broken finger — but built himself up slowly to become a pitcher with a future once more.

What Tolliver experienced Thursday became a true possibility last season, when, three full years removed from the surgery, he morphed into the pitcher he had always hoped to be.

The ball jumped out of his hand quickly in a compact delivery, touching 95 mph and sitting between 90 and 93, with a fastball he complemented with a swing-and-miss changeup at Bowie.

That was where he returned this year, pitching regularly out of the Baysox bullpen. Which made it odd when, in back-to-back extra-inning games Sunday and Monday, Tolliver didn't pitch. Gregg Tolliver thought it was strange, just as he did when he got an uncharacteristic postgame phone call from his son. Then it all made sense: Ashur would be joining the Orioles in Houston.

That set off what his sister, Autumn, called a tornado back in Arkansas. There were only a few cities in the majors that they could drive to for his debut on such short notice. Flying wasn't an option, with Tolliver's wife, Kelli, about eight months pregnant and unable to fly. Tolliver's sister is expecting, too. So they hastily packed and hit the road at 5 a.m. Tuesday, a seven-hour trek that would provide plenty of time for reflection.

“It was an emotional drive,” Autumn said, “just reflecting on the surgery, the hardships, the tribulation. It's just so exciting.”

That he made it back, and in the process became one of the more popular players among teammates in the Orioles organization, is something no one takes for granted. He credits the team. They credit him.

“I'm real proud of him,” Orioles manager Buck Showalter said. “He's a guy that has plied his trade for a long time and people tell him, [he] can't do this. I know there's a lot of people, obviously his family, happy to see him get to where he's wanted to get. … Good job by our scouting and player development people to hang on.”

In the eyes of the Tolliver family, good job by Showalter, too. Only Gregg was set to hop a plane to Cleveland to make sure he was present for a debut if it came to that. The expectant women and their mothers were set to make the seven-hour drive through stormy East Texas to make it back home whether he pitched or not. And they really wanted him to pitch.

“The way it worked out is pretty cool,” Ashur said.

He met the traveling party, which grew to include a few friends plus his mother, father, stepfather, sister and mother-in-law, in the bowels of Minute Maid Park, authenticated baseballs from his debut bagged up and sent back to Arkansas for safekeeping.

He'd thrown those baseballs harder than he normally does, topping out at 96 mph, and had them flying out of his hand in a delivery that gets the ball to the plate in barely more than one second. He and his teammates suspected he might be sore Friday because of it.

It will be a good sore, though. The kind that comes from a job well done, for the first time at the highest level.

“I've come back even stronger,” he said. “My recovery has gotten better and better every year, from bouncing back coming out of the bullpen. My arm speed has gotten better, a little bit better every year. That's completely behind me.”

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