Wing Seymour sustained a neck injury during Scotland's 55-6 defeat to South Africa on Saturday, ruling him out of action at Glasgow 2014.
But Scotland sevens head coach Stevie Gemmell insists the inclusion 22-year-old Hogg could prove a blessing in disguise.
"It's disappointing to lose Tommy but I'm delighted to be able to bring in a player of Stuart's calibre into our squad," Gemmell told the Daily Record.
"Stuart has shown at every level of his XVs career what he is capable of. He is a player who excites fans and has shown time and time again he can contribute significantly in both attack and defence.
"Although he has not yet played international sevens he comes from a background in the Borders that has been heavily influenced by the game.
"His game understanding along with the skills he has developed as a professional will I am sure prove a strong addition to our existing playing group. I'm excited about him joining the squad and contributing to a successful performance at Ibrox."