I have developed a sore left quad that seems directly related to serving. Lately I have been working on my kick serve and the constant pushoff upwards (right-handed serve) has given me a very sore left quad. Took a week off of tennis and it felt fine at first, but after a set, the left quad is sore again. So much so that I have to adjust my serve -- which unfortunately means that I lose much of the upward motion and power. After ice and rest, the pain goes away until I play again. Will this go away or do I need to take more time off of tennis?