For a goalkeeper of Andre Onana’s experience, the passage of play midway through the first half of Cameroon’s Africa Cup of Nations opener should have been routine.

Instead, it was anything but. Not once but twice, Onana misjudged the flight of the ball as it was crossed from one side of the field to the other. The second flap at thin air allowed Burkina Faso to take the lead, and left Onana with his head in the turf, acutely aware of his role in the chaos.

Cameroon would eventually rally, score twice and win to provide relief to the millions of fans who expect them to challenge for the tournament’s championship. Onana, too, would rally, eventually playing to the reputation of a man widely regarded as one of Africa’s best goalkeepers. But his rustiness could be explained by something everyone in Yaoundé’s Paul Biya Stadium knew:

For the better part of a year, Onana has hardly played soccer at all.

In October 2020, Onana failed a routine drug test after it revealed traces of a banned masking agent. He claimed, and investigators agreed, that it had all been an error: He was found to have mistakenly ingested the drug after confusing his wife’s medication for his own after complaining of a headache.

Rules are rules, though, and Onana was banished. For seven months, he was not allowed to even set foot inside a soccer stadium, let alone train with his teammates at his club team, the Dutch champion Ajax. And even when his ban was reduced last fall, and his drug exile ended, a new professional one began. Ajax, it seemed, had moved on while its goalkeeper was gone.

So for Onana, 25, this month’s Africa Cup of Nations championship is a rare opportunity to remind people of the player he was, and who he is: the skilled goalkeeper who helped Ajax win two Dutch league titles; the last line of defense for a team that came seconds from reaching the Champions League final in 2019; the anchor of a national squad hoping to regain a continental title on home soil.

That Onana can showcase his skills in his home country in the city he grew up in is making it all the more special.

“I was talking with my brother, and I said that I think I will know the whole stadium because we live close by,” Onana, 25, said in an interview on the eve of the tournament.

Many of Onana’s earliest memories, in fact, involve soccer. Playing in the streets for hours with friends. Walking to the national stadium to sit in the sun watching the national team. His first heroes were African, he said, stars like Patrick Mbomba or Joseph-Désiré Job who could bring the crowd to its feet just by returning for matches at the national stadium that sat a mere 20 minutes from Onana’s front door.

The national team was everything to Onana in those days. Cameroon had been one of the first African teams to become a fixture at the World Cup, and even as generations of players turned over, its matchdays offered a source of joy, and pride. Attending games, Onana said, was often an all-day affair.

“We were there five hours before the game just to watch 90 minutes,” he said. “And those 90 minutes could affect your week, your month. It was amazing that time to be honest.”

Onana’s journey to the national team can be traced to a pickup game before he turned 10. After spending most of the game tearing around the field in midfield or in attack, his preferred positions, Onana was told it was his turn in goal. He excelled, repelling shots that wowed his friends and also an older brother, who told him, “André, I think this is your best position.”

Within months he was named as the best goalkeeper at a tournament run by an academy set up by the Cameroon striker Samuel Eto’o. His performance earned him a trial, and eventually a move, to Eto’o’s academy in Douala, about four hours from home. There, his performances caught the eye of scouts from F.C. Barcelona.

Onana moved to Barcelona’s famed academy shortly after he turned 13. He quickly embraced his new surroundings, but three years into his new adventure, it all came to an abrupt stop. FIFA, soccer’s global governing body, announced that Barcelona had breached its regulations on registering minors by signing Onana and other players from outside Europe. Onana, 16 at the time, was told he could not represent Barcelona until he was 18.

While the club jettisoned most of the foreign-born players subject to the rule, Onana’s promise was so high that he was persuaded to remain in the academy, where he was allowed to continue practicing every day but not to play in official games. The hiatus from competition took its toll. “You can train as much as you like but in the end you train to play,” Onana said. “And if you don’t, it affects you mentally and physically.”

By the time Onana turned 18, and was again eligible to play, Barcelona had signed Marc-André ter Stegen, a promising German goalkeeper, and Claudio Bravo, who had just helped Chile win the Copa América. Onana knew, he said, his future lay elsewhere.

He decided to try his luck in the Netherlands, and within a year he had established himself as Ajax’s No. 1 goalkeeper. He was only 19.

The timing could not have been better. Ajax, like Barcelona, had a passion for homegrown talent, and the talents that had just started to come into its first team turned out to be its best in a generation. And the ball skills Onana had honed at Barcelona were a perfect fit for his Ajax’s style.

Success quickly followed, as did strong performances against richer clubs in European competitions like the Champions League. By the summer of 2020, some of those teams had started to circle, offering Ajax millions for its young goalkeeper. Ajax declined to sell, confident the price for Onana, and its other young stars, would continue to rise.

And then, just as it had a few years earlier, it all stopped for Onana when his drug test came back positive. Onana appealed the one-year ban he was given, and European soccer’s governing body accepted his explanation.

But under soccer’s regulations, he was still responsible, and so the punishment, reduced to seven months, meant that starting in February 2021 Onana was effectively ostracized from soccer. When his Ajax teammates lifted the trophy that spring to celebrate a title to which he had contributed, he wasn’t allowed to enter the stadium to watch.

He had, by then, made peace with his banishment. It was not, after all, his first. But Ajax officials, including the chief executive Edwin van der Sar, a former star goalkeeper, still worried about how Onana would manage the sporting and psychological toll of his time away.

“When I left the club, I said to Edwin, ‘This is nothing, I’m already used to it,’” Onana said. “He was like, ‘André, how?’ I told him I was banned for two years. So this is just one year. I’ve got this.”

To preserve his career, Onana assembled a team of seven specialists and moved to Spain, where he took training sessions every day in Salou, a beach town not far from Barcelona, to stay fit for the day his ban ended.

But because he has refused to sign a new contract in the interim, Ajax used Onana sparingly, starting him only twice since he became eligible to play again in November. “I think my time is over in Ajax already,” he said. “I’ve done my best for this club. But in the end I’m not the one who decides who plays or not.”

He expects to move on this summer, to another club, another league, another country. A switch to the Italian champion Inter Milan as a free agent for next season is all but agreed.

For now, though, Onana is back in Cameroon, back where it all started, back on the field, back with a team that counts on him.

The Indomitable Lions face Ethiopia on Thursday in the second game of their quest for an African championship. Onana sees no reason that he will not be playing.