May son injured his thumb playing football 2 weeks ago and he still has a great deal of pain from it. should we get it xrayed?

Probably.: It would be reasonable. A sprain can cause the same symptoms, but a missed fracture in a finger can cause permanent loss of function.

Yes: Although a sprain is the most likely cause of pain in a thumb injury, if the pain is not better in 2 weeks, it should be Xrayed to rule out a fracture. Hope this helps!

2 weeks: 2 weeks is a long time for a simple contusion or strain to cause his thumb pain. It is time to have his thumb examined to look for serious ligamentous injury or have an XR to look for a bony injury such as a fracture. All the best and I hope his thumb feels better soon.