Verstappen blocked da Costa's way to F1.
Antonio Felix da Costa has admitted his F1 "dream" is probably over.
Last year, the young Portuguese was the cream of Red Bull's driver development programme and apparently destined for a Toro Rosso debut in 2014.
But just as da Costa's Formula Renault 3.5 campaign faltered, Red Bull decided instead to pluck teen Daniil Kvyat straight out of GP3.
Max is a very, very good racing driver, and I could not have achieved at 16 what he has achieved.
Antonio Felix da Costa
Perhaps bolstered by the success of its daring choice, the energy drink company has now controversially decided to put 16-year-old Max Verstappen into F1 next year straight from F3 and karts.
In the meantime, Antonio Felix da Costa is acknowledging that his F1 dream may be over.
"At the start of the season I had hoped still to go into Formula One," he told Speed Week.
"But although I am only 23 and it's a bit young to give up a dream, I had to decide what to focus on, and that is DTM," da Costa said.
Still with Red Bull backing, he has raced a BMW in the premier German touring car series this year, scoring only 4 points so far.
But he insists that seeing first Kvyat and now Verstappen race ahead of him into F1 is "not hard" to cope with.
"I enjoy DTM very much and from the beginning it has gone well," da Costa said, "so I have decided to concentrate on this.
"If I was to spend ten years here, I would be happy," he insisted. "This is my goal.
"Max is a very, very good racing driver, and I could not have achieved at 16 what he has achieved. He is clearly a special talent," said da Costa.
"At the same time I am very sorry for Carlos Sainz jr," he added. "He was developed by Red Bull, they invested a lot in him, and he is now ready for promotion to the premier class.
"I hope he gets the chance and that we will see Max and Carlos on the grid next year."
In the meantime, da Costa is focusing not only on DTM, but also the all-new Formula E series, even though a clash last weekend meant he had to sit out the season opener.