Hello and welcome to HCM.
Thanks for putting up your query over here.
It seems that you have muscle
sprain.Based on symptoms you are telling,it will be too early to talk about any other possibility.Also you being sports person,makes the chances of muscle sprain more likely.
If I were your treating doctor,I recommend,
-Analgesics like iburofen or
naproxen to be taken orally for 3 days.Local application of analgesic gel like
diclofenac ointment over that area.
-Application of alternate ice packs and warm compress will help.
-Do some neck and back muscle relaxation exercises.
Look for these signs and symptoms to report to physician immediately -blisters,
cough,burning sensation spreading lower down to arm or legs,persistent pain or
stiffness in neck.
Hope this information helps.
Thanks and regards.