He was doubtful for the game after nursing sore ribs following last week's 36-13 win over the Sharks at Eden Park.
But Lavea has recovered enough to retain the No 10 jersey, allowing coach Peter Sloane to name an unchanged backline for the game at Newlands.
Lavea has been at the heart of a Blues revival over the past month and his recovery allows Luke McAlister to remain at second five-eighth, where he played a key role in their last two wins.
McAlister would have been moved to first-five if Lavea was sidelined.
There is one change in the pack where a fit-again Angus MacDonald gives the Blues some much-needed breathing space at lock.
The skilled utility will pair up with Bradley Mika in the middle row.
Sloane has stuck with the power of big rookie Nick Williams on the bench to cover lock rather than the specialist Chresten Davis.
Springboks coach Jake White wants the Stormers to inflict defeat on the Blues.
That would improve South Africa's chance of having a team in the semifinals, he said.
The Bulls are carrying South Africa's playoff hopes.
Stormers coach Gert Smal has moved Jean de Villiers from wing to centre, where many believe he plays his best rugby.
"It was always my intention to use Jean at centre at some stage, I never ruled that out and it was always in my plans" Smal said.
"You would have noticed that we moved Jean in from the wing for the last 25 minutes of the match against the Crusaders.
"He is a wonderfully creative player and he showed in the time he spent on the field what he could do in terms of creating something for the players around him."
Hanyani Shimange is fit again and returns to hooker, while Joe van Niekerk is back at No 8 after getting over his injury problems.
Stormers: Gaffie du Toit, Breyton Paulse, Jean de Villiers, De Wet Barry (captain), Tonderai Chavhanga, Chris Rossouw, Bolla Conradie, Joe van Niekerk, Gerrie Britz, Luke Watson, Rob Linde, Andries Bekker, Faan Rautenbach, Hanyani Shimange, Eddie Andrews. Replacements: Pieter Dixon, Riaan Olckers, Ross Skeate, David Hendriks, Neil de Kock, Marius Joubert, Gus Theron.
Blues: Mils Muliaina, Doug Howlett, Ben Atiga, Luke McAllister, Joe Rokocoko, Tasesa Lavea, Steve Devine, Xavier Rush, Daniel Braid, Jerome Kaino, Bradley Mika, Angus MacDonald, John Afoa, Keven Mealamu, Tony Woodcock. Reserves: Derren Witcombe, Saimonie Taumoepeau, Nick Williams, Justin Collins, Ben Meyer, Rua Tipoki, Isa Nacewa.