Ajax set up next month's showdown with Amakhosi by beating De Sa's former club Bidvest Wits 2-1 on aggregate on Sunday.
Chiefs advanced by defeating Bloemfontein Celtic by the same scoreline last night.
While De Sa is naturally pleased to be in with a shout for silverware, he is mindful of keeping his charges alert for their upcoming assignments in the Absa Premiership.
The Urban Warriors, who are a point behind League leaders Mpumalanga Black Aces after three games, next host Polokwane City at Cape Town Stadium on September 9.
De Sa said: "Next is the League. We won't worry about that [the Final] until we get there. We have a couple of League games first, then when we get to the week of the Final we will think about it."
The 50-year-old was pleased with his side's work-rate in their 1-0 win at Wits on Sunday, but felt they should have scored more goals after Siyabonga Nhlapo was sent off at Bidvest Stadium.
"I thought we did well, we had a couple of chances to wrap up the game. Moeneeb [Wits goalkeeper, Josephs] was magnificent, he made one or two good saves.
"The boys worked hard, they ran out of legs a bit, we could have punished them more."