Though Maria Sharapova and Serena Williams have already played today, there are top matches still awaiting in Day 4 of Wimbledon.

Rafael Nadal (2) is awaiting the Ivo Karlovic and Andy Murray (4) draw to finish up in Centre Court, before he faces Lukas Rosol (100).

For Nadal, the matchup should be a breeze. Roscol has only been into the 3rd Round of a Grand Slam tournament once in his three-year career as a pro.

Jo-Wifried Tsonga (5), will face Guillermo Garcia-Lopez (92) in the last match in Court No. 3.

Tsonga has shown a lot of potential throughout his career. In 2008 he finished as the runner-up in the Australian Open after losing to Novak Djokovic.

Last year, Tsonga made it all the way to the Semifinals at Wimbledon and followed with a performance into the Quarterfinals at the U.S. Open. He was also a quarterfinalist in this year's Roland Garros.

Also in later action, Juan Martin Del Potro from Argentina (9) will play against Japanese, Go Soeda (58).

This is the first time Soeda makes it past the first round of a Grand Slam tournament.

He will go up against a 23-year old Del Potro who has made quarterfinalist appearances in this year's Australian Open and Rolan Garros.

In the Ladies' Singles, the 2nd ranked player awaits for Andy Roddick and Bjorn Phau to finish up their matchup on Court No. 2.

We know Sharapova is the No. 1, but do you know who the second best female tennis player is coming into Wimbledon?

Her name is Victoria Azarenka, from Bulgaria.  She won the Australian Open this year and is just 22-years old. 

Azarenka will be facing Romina Oprandi (87). 

Also do not miss Anastasia Pavlyuchenkova (31) play against Varvara Lepchenko (53) on Court No. 17.