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The match of the day on the men's side will feature Roddick against Wawrinka.
The Swiss is doing everything in his power to follow his master countryman Federer.
As a matter of fact he decided to hire the 29-year old's former coach Peter Lundgren, who helped him climb to the World No. 9 spot, his highest rank ever.
The 19th seed already has one of the best one handed backhand in the world , while Lundgren helped Wawrinka improve his serve to become the player he is now.
That is why Andy Roddick faces a difficult clash against the World No. 19 on Sunday.
The American bounced back from a first set loss to defeat Robin Haase in the third round, and seems to be in decent form, while the St. Barthelemy native has won all of his matches in Melbourne in straight sets. His most recent outing, where he defeated Gael Monfils, indicates that he could really threaten the Austin resident on Sunday.
This pairing has a slightly unusual head to head history. Wawrinka leads 2-1, though both of his victories came through first set retirements.
The only competitive match to be completed between the pair was played on a hard court in 2009, with Roddick securing a comfortable 6-4 6-4 6-2 win when the USA received Switzerland in a Davis Cup first round encounter back in 2009.
This match could easily turn out to be a grueling five-setter.