When an athlete complains of a pulled groin muscle it may be a more serious injury, e.g., a pelvic stress fracture, avulsion injury, and even a tumor can be confused with a groin strain.
The "groin strain" is an injury that needs to be thoroughly examined, palpation needs to be extent and well done. A complete history and special functional test will help to open up other possibilities, but you need to consider them carefully. If you believe a stress fracture or avulsion injury is present then send for x-rays. Consider other possibilities seriously and treat them accordingly.
Treatment needs to be started right away. Start with the basic R.I.C.E. to suppress pain and muscle spasm. All clinical "muscle pulls" involve some degree of muscle rupture, vessel tearing and bleeding. Rest and compression will usually help to lower the amount of bleeding. Ultrasound has been a common use, but caution should be exercised in acute stages of groin strains because of possible microbleeding.
Groin strains are injuries that are often over looked and not examined thoroghly. Treat groin pain as something more serious until it is proven otherwise.