Mine do it frequently when they get a goat head sticker in it. (I don't know what they are really called, but that is what my husband calls them.) Even after it has been removed they favor the leg a few minutes because the sticker must have some type of stinging agent in them. That's the only time I notice them having a leg issue though.
actually diesel just got over this... he was really gentle with it and would limp on. also when standing still (if that ever happens) he would lift it up.
so after a few days and not finding anything in his paw or between his pads we went to the vet
so i would just keep an eye on him for a few days.
touch his leg all over and see if he flinches in one particular area. he might have somethin stuck in his paw hiding under the fur between his toes. so look carefully