The Spanish striker failed to make the grade at the White Hart Lane club in 2011. He went out on loan, before finally finding his footing in Italy.
"Maybe the move to Tottenham, it was not a wise decision on my part," the 28-year-old is quoted as saying by Goal.
"It was the only step back in made in my career.
"In the end, bad experiences also help you to grow, to mature. It was the momentum in my career that made me sign and the competition was very hard.
"Now my priorities are more about the sport rather than the financial side. Money comes later - after games, goals and good performances.
"I don't regret it, per se, because it matured me."