Nadal cracks up in adorable ad for Brisbane International

Video has emerged of a sheepish Rafael Nadal struggling to keep a straight face during a promo for the Brisbane International.

The World No.1 will return to the Brisbane event in January to prepare for the Australian Open.

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And in a new video released by Ticketek Australia, Nadal cracks himself up while letting fans know how excited he is to be coming back to Queensland.

As you can see above, the Spaniard gets through his lines fine but insists on a re-do as he breaks out into a massive smile.

How good is Rafa! Image: Ticketek Australia

We dare you to watch the video without smiling along with him!

Nadal will headline the Brisbane International, which runs from December 31 to January 7, for the second straight year after parlaying his Brisbane form into a run to the final at Melbourne Park in January.

Nadal in Brisbane earlier this year. Image: Getty

Former winner Milos Raonic and this year's runner-up Kei Nishikori are also set to return.

Canada's Raonic, the former World No.3 who defeated Roger Federer in the 2016 Brisbane final, will be playing in the Australian Open warmup tournament for the fourth time.

"The conditions are ideal for preparing leading into Melbourne (Open) and the whole Australian swing. I think it's the best way to start off alongside the best players in the world," Raonic said.

Japan's Nishikori is lining up his eighth trip, aiming to go one better than his runner-up effort to Grigor Dimitrov this year.

"I hope I can make the final, but my goal is to win the tournament. It's the first tournament of the year so I'll try and have a great tournament," he said.

Raonic and Nishikori will join a strong men's field that is headlined by Nadal, Andy Murray, Nick Kyrgios and Dimitrov.