Board Thread:Naruto Discussions/@comment-24898250-20140730025315/@comment-26302001-20140731053147

@Elve, in the Databooks Stamina and Chakra are covered by one stat. As the first Databook explains clearly. There are translations all over the internet for it and Gai has a 5 in it meaning he is 5th tier in chakra and stamina. So yes, Gai does indeed have the capacity to become Sage.