sweat and saliva won't transmit anything to you unless he is absolutely gushing saliva into an open sore of yours. It would take a lot.
Blood, however, if it got into an open sore or a mucous membrane of yours, could definitely transmit something.
you have no risk...STD's are not spread by that manner...you have to have unprotected sex...oral, vaginal or anal to transmit STD's.
Wrestling will put you at risk for anything that can be transmitted via skin-to-skin contact. Herpes (HSV-1 & HSV-2) can be contracted via wrestling due to the sweat and blood all coming in contact with bare skin. Transmission of Syphilis is also possible, as it is one of the few STDs that can be obtained through casual contact.
Much of this risk can be avoided by cleaning the wrestling mats with disinfectant following each match. A friend of mind contracted HSV-2 on his scalp after practicing on a dirty wrestling mat in high school. No fun.
any wrestler who knows he/she has herpes simplex, should be on daily suppressive therapy during wrestling months. This is pretty much the standard for all wrestlers regardless if they are in high school or a professional wrestler.
mrsa is probably just as big a problem as anything else.
grace