Back in 2013, da Costa, as part of the Red Bull Junior Team, was a prime contender for a Scuderia Toro Rosso seat the year after, but the energy drinks giant opted to promote Daniil Kvyat instead.

The Portuguese racer has since moved on to Formula E and the DTM, having won races in both - but he concedes it's still difficult to accept that he never made it to F1.

"Formula 1 is still the king category of the sport," da Costa told Motorsport.com.

"I really try to abstract myself from the fact that I'm not there. But I'm now doing commentary for the races in Portugal, and it's really hard when I look at guys - most of them very talented - but lots of people there that I've raced with and beaten them. And I see them actually doing well there.

"I know that I could've done well there, there's a difference between doing well and being a world champion, but I've worked on my mind pretty well to abstract from that. Some days I feel better than other days, let's put it like that.

"But, you know, a race driver's career is not over if you don't go to F1, I'm super lucky to be with a manufacturer [BMW] that's known in Portugal, Germany, Malaysia, Thailand - very prestigious for me and I can't complain."

Kvyat "deserves a decent chance" to recover

The 2016 Formula 1 season has been a tough one for da Costa's former RBJT rival Daniil Kvyat, the Russian faced with a demotion from Red Bull's main team four races into the campaign.

Da Costa has backed Kvyat to recover from his current slump in form, however, saying that he has done "very good things in F1".

He said: "Dany is a super talented guy, but when you put these young guys in F1 and they're not ready - not only talking about Dany but I could even put Carlos [Sainz] in the mix, I could put Max [Verstappen], I could put all of these young guys who joined F1 - it's fine when everything is good, it's super easy, it's easy to cope with good pressure.

"But as soon as you have a problem, it becomes hard and you see the young kids suffering a little bit more than the established guys. Which is normal, but Dany has done very very good things in F1, especially his rookie season has been very impressive against JEV [Jean-Eric Vergne].

"I believe he deserves a decent chance. I don't think what was done was right, but it is what it is and now he needs to cope with it, and now we have to see if he's strong enough.

"I hope he is, I know him well, I still speak to him now and then. And I hope he gets the upper hand on it."

Asked if there were any hard feelings between him and Kvyat as they had vied for the same seat three years ago, da Costa said: "Not at all. I mean, it's not his fault.

"If I had the chance to take an F1 seat from someone else, I would do it. My friends are the guys I've known since I was a kid.

"The guys I race with, yes, they are nice guys and I like to hang around them, but at the end of the day, you need to look out for himself - and that's exactly what he did and I cannot blame him for that."