The England hooker, who three years ago retired from the game because of a neck injury only to make a stunning return for club and country, joined the ambitious Yorkshire club on a two-year contract in the summer.
Thompson was one of 11 summer recruits – seven of whom are named in the match-day 23 for tomorrow's mouth-watering opener – but in a selection that says much about the strength of the squad Andy Key and Neil Back have assembled, the 32-year-old finds himself only second-choice hooker.
The starting No 2 jersey goes to Andy Titterrell, a one-time England international who joined Leeds last November and was instrumental in their successful survival fight in their first season back in the big time.
Thompson will get some game time tomorrow as a second-half replacement and the fact that he starts from the bench illustrates that Key and Back have been successful in creating competition in vital areas through high-quality additions.
"We think the balance for this particular game is better with Titterrell at hooker and Thomo coming off the bench," said director of rugby Key.
"As we develop through a long season, the strength of our squad will be reflected not only in the 15 who take the field, but the 23 named on a match-day and those who are not involved."
Two former Bath players line up against their former employers with Michael Stephenson starting on the wing and Daniel Browne debuting as No 8.
Leeds have reinforced their backline during the summer with New Zealand international Lachlan Mackay starting at inside centre and former Bradford Bulls rugby league star Semi Tadulala making his Premiership bow on the wing.
Miguel Alonso is the other debutant, lining up alongside his fellow Argentinian-born prop Juan Gomez in the front row.
England captain Lewis Moody debuts for Bath who many pundits tip to end Leicester's recent dominance of the Premiership.
Another former Tiger, Sam Vesty, is at fly-half, while Tadulala's former Bulls team-mate Shontayne Hape starts at 12.