Adrien Costa, one of the most talented young American riders of this generation, will not return to professional racing with the Hagens Berman Axeon team in 2018.

On Monday afternoon, the team announced that the 20-year-old phenom had relinquished his spot on the roster. Costa took a break from professional cycling in July 2017. Team management hoped he would return in 2018.

“I’m just not ready to come back yet,” Costa said in a release. “The more I thought about it, the more I realized I didn’t want to hold a spot on the team when that meant denying someone else the opportunity.”

Costa turned heads in 2016 with a flurry of major international results, winning the youth classification at Belgium’s Le Triptyque des Monts et Chateaux, before becoming the first American to win France’s Tour of Bretagne. Later that summer Costa finished second overall at the Tour of Utah, where he also won the youth and mountains classifications.

The major results set the stage for Costa to break out on the international circuit in 2017. But after a quiet spring, Costa revealed that he was taking a break from racing altogether, citing fatigue.

In the team release, Costa said he was concerned that racing and training had taken over his life to an unhealthy degree.

“Since I stopped racing in April 2017, I’ve learned a lot about myself and realized how big, and unbalanced, of a part of me was cycling,” Costa said. “I knew that if I was going to race again, it’d be in a much different, more relaxed way. I wasn’t able anymore to have the single-minded, razor-sharp focus for training and racing that I once woke up with daily. I knew I had to lean on other things in life to provide me more balance and more happiness overall.”

Last month team director Axel Merckx told VeloNews that he had been in regular contact with Costa and that the California native was back on his bike training. Merckx said he expected to see Costa at the team’s February training camp in Southern California.

“I respect his journey,” Merckx said. “He knows everyone is here for him.”

Costa said he plans to attend Oregon State University where he is pursuing an undergraduate degree in outdoor leadership and tourism.

To fill Costa’s spot the team has hired 21-year-old Sean Bennett, who raced for CCB Foundation-Sicleri. Bennett won the mountains classification at the 2017 Tour of Bretagne.