The Spanish striker joined the club on a free transfer from Athletic Bilbao in the summer and claims that he found it hard to compete with his rivals for a spot in attack.
"I could hardly train as my body simply couldn't keep up. My body was not used to working so much and I felt completely drained. I had a lot of doubts and was ready to throw in the towel," Llorente told La Gazzetta dello Sport.
"Also because there is a lot of competition for places. We are with five attackers and it's not easy to break into the team.
"But then Antonio Conte considered me again and that gave me a lot of energy. I was fortunate enough to get more playing time."
Llorente has scored four times in 12 appearances for Juventus.