Originally Posted by: Passey01...I have a new Fender Stratocaster Deluxe Player. It fell off a chair last night and a small black spring fell out of the back plate.

Sounds like a classic 5-way switch spring. Look here:

http://www.premierguitar.com/Magazine/Issue/2009/Feb/The_Anatomy_of_the_Stratocaster_5_way_Switch.aspx

Does your pickup selector seem broken or loose?