Brisbane - US Open champion Marin Cilic and runner-up Kei Nishikori will use the Brisbane International as their lead-up to next year's Australian Open, tournament organisers said on Thursday.
Croatia's Cilic claimed his first Grand Slam title in New York earlier this month with a straight sets win over Nishikori, the first Asian man to reach a Grand Slam final.
Cilic has jumped from No 37 at the start of this year in the ATP rankings to a current nine.
"This year I played in Brisbane for the first time and I really loved the tournament so it was one of the obvious choices to come back again next year," he said in a statement.
"Knowing I have this Grand Slam in my closet for sure it will bring me more freedom in my game and mentally I know what I need to do to achieve this kind of accomplishment."
Nishikori will return to Brisbane for a fifth time, having competed at the event in 2009 and every year since 2012.
The pair join 17-time Grand Slam champion Roger Federer in the men's draw for the tournament from January 4-11.
Next year's opening Grand Slam, the Australian Open, takes place in Melbourne from January 19-February 1.