If you scroll down the list it seems fairly clear that Cruz will be introducing Trump's VP candidate and he will be Gingrich, if they follow the pattern on previous republican conventions.
http://www.12news.com/news/nation-now/trump-convention-highlights-family-members-celebrities/273023915
http://www.12news.com/news/nation-now/trump-convention-highlights-family-members-celebrities/273023915