need help! groin injury from running

I'm posting this for my husband and hoping to find some help. He is a runner, has run for years, finished his first official 1/2 Marathon in May and is/was planning on doing his first Full Marathon in 2 weeks. HOWEVER... 2 weeks ago, he went running and came back hardly walking. One of his feet felt like it was on fire and one side of his groin was so sore that he could hardly walk. He figured that he was probably compensating for the pain in his foot, so took a couple days off. He started up again and 1 week ago ran 20 miles. He felt great- just "tired" legs. He took the next day off, then ran a short run- about 6-8 miles. He came back hardly walking again and now, he can't hardly even lift his one leg. (He does run quite fast on the short runs- usually about 7 min. pace.) He's iced, stretched and rested, but this time it doesn't seem to be getting better. Anyone have any ideas? Thanks. ~Rachelle