It is the case that tennis players who play intensively, whether professionals or not, have a high absolute risk of stress fracture. I am not sure that the evidence shows they are suffering actual fracture more than other sportsmen.
A recent study of elite tennis players showed that the lower extremity was more affected, but upper limb stress fractures were also often found. The most often found bone injury sites were the navicular, the metatarsals, and the pars interarticularis. The study concluded that the highest risk of fracture comes from Junior male players involved in intense tennis training .