"Rory is the second favorite," Harrington said on RTE's Game On. "At the end of the day, DJ is playing the golf of his life at the moment, he's peaked, he's really on form. There are a number of great players in the game at the moment, but I get the feeling that they are all looking over their shoulder and looking at other players, worried about other players. When Tiger was number one in the world, he was never thinking about anyone else. He knew his 'B' game was going to beat everyone else. With the way DJ is playing, Rory is going to be under pressure to bring his 'A' game and that's tough enough."
Coming in after three-straight wins, Johnson's odds to win the season's first major are 11/2. McIlroy currently sits at 15/2.
"DJ doesn't think very much, I don't think DJ looks over his shoulder," Harrington continued. "I don't think he worries at all. DJ is the most likely one to play his game next week, and if he does turn up and perform, he'll be the winner. Rory is the only one capable of beating him at this very moment.”
A win for McIlroy would mean the career grand slam and fifth major championship for the 27-year-old McIlroy. Harrington himself played in 15 Masters but never finished highest than T5. He'll be in the booth for Sky Sports next week for its broadcast at Augusta National.