After claiming a spectacular victory atop Mt Etna on stage six of the Italian Grand Tour, Chaves unexpectantly dropped out of overall contention on stage 10 and struggled through the rest of the race.
Subsequent to the finish of the race, a number of tests were ordered on Chaves and he also underwent minor sinus surgery.
“It’s been a hard period," said Chaves. "Since 2012 I haven’t been off the bike this long, especially because I can’t. It was not fast like you want. In this sport, we are used to answers and results coming fast and this process was slow and the time can make you crazy.
“But, we worked really well with the team and I want to thank you them for their support and patience, from the head with Shayne and Gerry, to the masseurs and mechanics that have been close to me in this process."
The 2016 Il Lombardia champion will not line up as previously planned at the upcoming Vuelta a Espana and there has been no final decision as to whether he will race again in 2018.
“We discovered some sickness, the doctors can always explain better, we had a surgery as well, and after that it was just waiting and having confidence to overcome what was a weird case.
“I’m happy to be back on the bike. It still hurts for sure, but I can already feel some differences; it’s a different suffering than I had before. Now it’s the normal suffering we get when starting again after such a long time off training.
“We are on the right path again and we have to keep patience and confidence like always.”
Manuel Rodriguez, Mitchelton-SCOTT's doctor, elaborated on the medical issues for Chaves.
“After thorough testing, Esteban was diagnosed with Epstein-Barr virus as well as chronic sinusitis process.
“Epstein-Barr is not a new virus nor an uncommon one, but in Esteban tests showed that it was gaining strength and attacking when his immune system was down or in times of fatigue, most obviously in races or high intensity training periods. Its strength likely allowed the introduction of other viruses into his body.
“After a period of rest and treatment for the viruses, Esteban was cleared for minor sinus surgery before undertaking a final recovery period.
“We are confident that the treatments have been successful and it is safe for Esteban to return to training but to prevent the reoccurrence of symptoms we will monitor his health without a deadline to return to racing.”
Chaves is one of the key riders in Mitchelton-SCOTT's grand tour focused setup, with the Colombian having taken overall podium finishes at the Giro d'Italia and the Vuelta a Espana.