Diagnosis: Sportsman Hernia

The symptoms described – severe, debilitating groin pain extending into the scrotum and thigh, aggravated by exercise, along with tenderness in the inguinal canal and pubic tubercle – are highly characteristic of a condition often referred to as Sportsman Hernia or Athletic Pubalgia.

Key Indicators for Sportsman Hernia:

• Patient Profile: Young sports person.
• Pain Characteristics: Severe, debilitating groin pain radiating to the scrotum and thigh, impacting athletic activity.
• Location of Tenderness: Inguinal canal and pubic tubercle area.

Why Other Options Are Less Likely:

• Varicocele: Typically presents as a dull ache or heaviness in the scrotum due to enlarged veins, not sharp, debilitating pain localized to the inguinal region and radiating as described.
• Inguinal Hernia: While possible, the term "Sportsman Hernia" specifically addresses the type of groin pain syndrome common in athletes, often involving subtle inguinal canal wall damage rather than a large bowel protrusion. The specific location of tenderness also points more strongly towards sportsman hernia.
• Femoral Hernia: This type of hernia occurs lower in the groin, through the femoral canal. It's less common in young males, and the primary tenderness is usually below the inguinal ligament, differing from the described findings.

Therefore, considering the specific combination of symptoms, examination findings, and the patient's profile as a young athlete, Sportsman Hernia is the most probable diagnosis.