Bristol duo Phil Christophers and David Rees start at outside centre and right-wing respectively, while former Worcester man Tim Walsh gets a start at fullback.
Scottish fly-half Duncan Hodge makes his debut in the absence of World Cup countryman Gordon Ross, while former Gloucester squad member Clive Stuart-Smith also starts.
In the pack, ex-Saracen Stuart Hooper is among the debutants, as is Irishman No.8 Colm Rigney.
Dual-code signing Liam Botham only earns a place on the bench after featuring for the Tykes' sister Rugby League club, Leeds Rhinos, while former Wales fullback Matt Cardey is also among the replacements.
Leeds' Welsh coach Phil Davies said of the game ahead and his side's off-season: "There have been a lot of new arrivals to the club during the close season. When we began planning for this season we recognised that we needed to bring down the average age of the squad to provide longevity to what we are trying to achieve.
"We have brought in some extremely talented young players such as Clive Stuart-Smith, Phil Christophers, Stuart Hooper, Scott Morgan, Gary Powell and Tim Walsh, who are all 24 years of age or younger.
"Our Academy is producing quality players who are graduating to first team level and I was delighted to have six players from the Academy involved in our win over the Borders in pre-season."
Of Sunday's opponents, Davies added: "Bath will set us a tough challenge on Sunday. They have recruited well in the off season and there appears to be a real buzz about them from their pre-season form. John Connolly is a quality addition to their coaching staff having coached successfully at the highest level.
"I'm sure they will have been disappointed to lose Mike Catt at late notice but because of Mike's unfortunate run with injuries over the past 18 months it is not something they will have a problem coping with.
"They have a strong front five led by Jonathan Humphreys and we will have to match their intensity up front if we are going to be able to perform to our best.
"This season is going to be our hardest season yet, with the World Cup playing its role, and also expectations being high after our success last year, but we're all confident.
"Last season the league was extremely competitive with everything going down to the last game and with the addition of Rotherham I feel the Premiership has got even harder."
Leeds Tykes: 15 Tim Walsh, 14 David Rees, 13 Phil Christophers, 12 Tristan Davies, 11 Dan Scarbrough, 10 Duncan Hodge, 9 Clive Stuart-Smith, 8 Colm Rigney, 7 Dan Hyde, 6 Matt Salter, 5 Scott Morgan, 4 Stuart Hooper, 3 Matt Holt, 2 Rob Rawlinson, 1 Mike Shelley (captain).Replacements: 16 Gary Powell, 17 Michael Cusack, 18 Stewart Campbell, 19 James Ponton, 20 Alan Dickens, 21 Liam Botham, 22 Matt Cardey.
Kick-off: 14.30 BST (13.30 GMT)