Chelsea are set to pay around £15million for the 28-year-old Brazilian, who is set to complete his move to the club in the next 48 hours.
Luis admits that it was difficult for him to decide to leave Atletico Madrid, but he could not reject the chance to join Chelsea.
"I never thought about leaving Atletico, but I took the decision because of the offer which came from Chelsea," said Luis.
"A change of team gives new hunger and ambition, and I was worried about being too comfortable here. A footballer’s career is very short and I want to finish it in a strong and spectacular way."
Luis even claims to be a Chelsea fan.
"I have always liked Chelsea a lot. I watch a lot of the Premier League and it is a club where you can feel the warmth of the fans," he continued.
"When we played there in the Champions League I felt comfortable in their stadium and when the offer came I thought it was the ideal team for me to play for in England."