You've done pretty well, Edu, to get this. With action shots there is little time to react so perfection is hard to achieve without a lot of experience.
In this instance you have clipped off the top of the racquet and perhaps included too much of the ground. A slight tilt upwards of the camera at the crucial moment could have avoided this. The lighting is harsh so inevitably there is a slight loss of detail in the highlights. Some,but not much, can be retrieved by used of the shadows/highlights tool in PS. Cropping the foreground may also help.
But overall a decent effort.
I've uploaded a mod for you which reflects my comments.