Halep was beaten 6-1, 2-6, 3-6 by Maria Sharapova in 2014, but she believes that her fortunes will take a turn for the better this year.
"I was very excited to play in the finals of a major tournament as Madrid," Halep told the Mutua Madrid Open's official website. "This match, even if I lost it, gave me a lot of confidence.
"I'm looking forward to playing in this wonderful tournament again."
Having won at Indian Wells and reached the semi-finals in Miami and Stuttgart prior to this, Halep is confident that she can add the Madrid Open title to her collection.
"It would be very emotional to win this trophy," she said. "The Mutua Madrid Open is a big tournament, almost as important as a Grand Slam. It's more than preparation for Roland Garros. It's a tournament I'd love to have in my record book as a champion."