EE WAS WALKING THRU TUNNEL WHEN ALERTED TO SHUT DOWN CONVEYOR. MADE A QUICK PIVOT MOTION TO RT. LEG, FOOT WAS IN A PILE OF GRANUAL. HE STATES THAT HE FELT A POP AND BURNING SENSATION BUT DID NOT PRECEIVE IT AS ANYTHING TO WORRY ABOUT. HE REPORTED IT TO HIS SUPERVISOR, BUT DENIED NEED FOR MEDICAL ATTN. PAIN INCREASED OVER THE WEEK, TRANSPORTED TO CVIC FOR DX OF RT. KNEE STRAIN.