World No.5 Kei Nishikori hopes to be fine for the Australian Open after withdrawing from a Sydney exhibition event to nurse a hip injury.

The Japanese superstar said he pulled up sore after losing a three-set final to Grigor Dimitrov at the Brisbane International on Sunday.

Nishikori, who has been troubled in the past by hip and rib injuries, said it was best to take no risks a week out from the season’s first grand slam getting underway in Melbourne next Monday.

“I hurt it during the match yesterday in the final. It’s not too bad but obviously I needed some rest,” Nishikori said after pulling out of Monday night’s Fast4 event.

The 2014 US Open runner-up played four matches in Brisbane, beating reigning Flushing Meadows champion and world No.4 Stan Wawrinka in the semis the day before the final.

“It was a really tough tournament,” Nishikori said. “There were five of the top 10 in the tournament.

“I played Dimi in the final and it was another tough match and I used a lot of energy on the court last week.”

Nishikori will be seeded fifth at Melbourne Park, where he has been a quarter-finalist three times, including last year when he lost to eventual champion Novak Djokovic.