American forward Stephen Lumpkins, here in December battlin with Georgetown’s Otto Porter Jr., could play professionally in Europe, Eagles Coach Jeff Jones says. (John McDonnell/THE WASHINGTON POST)

Another bad day had confirmed it for the big left-hander: He didn’t belong here.

Stephen Lumpkins was, for about a year, exclusively a rookie league pitcher. Now it was a choice he regretted.

After this poor outing, when Lumpkins issued four consecutive walks before the manager removed him, he sat frustrated in the Arizona heat and decided he should be elsewhere: a place he’d left, that basketball court in Washington.

“I was trying to be something I wasn’t,” the 6-foot-8 Lumpkins said last week.

He would return to American University, where he had played three seasons, to complete his basketball career. But at the time, things didn’t seem so simple. Lumpkins had surprised Eagles Coach Jeff Jones in April 2011 with news that his attention now belonged to two sports. Two months after that meeting, the Kansas City Royals drafted Lumpkins in the 13th round of the first-year player draft, and he was gone.

“Let’s just say I didn’t take that news too well,” Jones said.

This is life when youngsters are involved, especially one with surprising talent. Lumpkins, 22, hadn’t talked much about baseball, because there wasn’t much to talk about. He had played in high school but didn’t pursue a baseball scholarship or attend a school that offered a chance to play both sports. American doesn’t have a baseball team.

Lumpkins became a reliable basketball player, but Jones also knew him as a timid young man. Lumpkins had trouble looking his coach in the eye during conversations, but he listened and became one of the Eagles’ most promising players.

Then one summer, he returned to his native Redwood City, Calif., passing the time on the local American Legion baseball team. He pitched a few innings and found that his fastball now reached 90 mph. It caught the attention of pro scouts, and Lumpkins was invited to show off his velocity in private bullpen sessions.

He returned to Washington and gave little thought to his other game. In 2010, though, the Pittsburgh Pirates selected him late in the draft. “Kind of out of nowhere,” he said.

He passed on a contract offer, but wondered whether abandoning baseball had been a mistake. After his junior season at AU, Jones invited his best player into his office. There were things Lumpkins could do to advance his game. So many things were possible, but only if he . . .

Wait, Lumpkins told Jones. There was something else. If he ever planned to try baseball, this was the time. He told Jones that he would spend part of his summer on baseball fields. The decision had been made, and as he said it, Lumpkins looked Jones in the eye.

“I definitely raised my voice,” Jones said, adding that he was upset because he had no idea Lumpkins was even considering baseball.

The problem wasn’t just that Jones had high hopes for the Eagles in 2011-12. He had pursued a promising recruit weeks earlier but had no scholarship available. If Jones had known, he might have used the scholarship that Lumpkins was giving up.

“His plans and our plans kind of, they didn’t match up,” Jones recalled in his office at Bender Arena. “We had high expectations for him.”

That June, Kansas City drafted Lumpkins and offered him $150,000 to sign. The Royals insisted that their offer was good only if he quit basketball, though the team agreed to pay for his final year of classes.

Lumpkins started low in the farm system, and his talent was raw. After a few weeks, the Royals asked Lumpkins to alter his pitching motion to use his height and deliver the ball from a higher angle. Lumpkins agreed, but the change was uncomfortable and affected his control.

“I was trying to catch up,” he said, “and as I was changing, I was getting further behind.”

After the outing last July, when he was relieved after several walks, Lumpkins determined that, even in time, he’d be unable to make the changes the Royals had suggested. At 22, he retired from baseball but retained his signing bonus and the promise that his school would be paid for.

Lumpkins called an AU assistant basketball coach, who mentioned to Jones that Lumpkins was considering a return. Jones thought about it, but would the kid be committed? He had already walked away once.

“I guess if there was a worry on Lump’s part about somebody carrying a grudge,” Jones said, “they would be worrying about me.”

The coach said he spoke twice with Lumpkins, who reaffirmed his desire to play. He had started his career at American, and now he wanted to finish it. Jones said the talks convinced him that Lumpkins’s failed baseball experiment had matured him.

With Jones’s blessing, Lumpkins returned to campus, starting conditioning drills last August, before his teammates reported for practices. He finally felt at home. Jones saw an opportunity in the Patriot League with two skilled post players, Lumpkins and power forward Tony Wroblicky, who had taken Lumpkins’s place down low but had to make room for his return.

Jones said the past drama with his best player is mostly forgotten. “He did something that he thought he needed to do,” the coach said.

Sitting in a back room in the Eagles’ basketball office, Lumpkins chuckled when asked whether he’s finished with baseball. He said he’s a basketball player, and it took him leaving the game to realize that.

Jones said Lumpkins, who leads AU (10-19) in scoring and rebounding entering Wednesday’s Patriot League tournament quarterfinal at Army, could play professionally in Europe.

He asked Lumpkins whether he remembered those early days, when he was so reserved. The basketball player smiled and nodded, looking his coach in the eye.

“I’ve come a long way,” Lumpkins said.