Thank you for your query at DoctorSpring.com
I have read your question with diligence .
I have gone through x ray.It looks that he had fracture above epiphysis of distal phalanx of thumb.The Astt or nurse had done right to reduce the fracture on sight.At present his injury is stable injury.You should not bother about this.
Our bones generally able to heal by forming sticky substance by about 3 weeks.At present his fracture is stable by splint but he should be cautious in using it heavily &excessively till 3weeks.He can pitch with brace off after 3 weeks.After 4-6 weeks he can use his thumb at any extent.
At present with brace he can play upto his pain level but as per my previous statement he should not use it heavily.
Hope this will help you.