Mutua Madrid Open - Wednesday Matches to Watch

Most of the top players in the world hit the blue clay on Wednesday.

Here's what to keep an eye on:

Men

Nikolay Davydenko vs. Rafael Nadal - Rafael Nadal makes his debut on the blue clay.

Roger Federer vs. Milos Raonic

John Isner vs. Marin Cilic - A lot is now expected of Isner on clay.

Ryan Harrison vs. Jo-Wilfried Tsonga - Harrison is due for a big win.

Women

Agnieszka Radwanska vs. Sara Errani - Errani has won 3 clay court events in 2012.  She's legit.

Victoria Azarenka vs. Ana Ivanovic

Angelique Kerber vs. Na Li

Sam Stosur vs. Petra Cetkovska