Red Bull remained absent from challenging the best times during the first test in Barcelona, with Ferrari looking to have the strongest package so far.
This year the team will be powered by Honda engines alongside Toro Rosso, who had an impressive first test, going fastest on the third day of testing.
Red Bull could win races other than at ‘special circuits’
However, Marko believes that his drivers of Max Verstappen and Pierre Gasly can be successful this season – and not just at tracks where Red Bull would be strongest.
Speaking on the fourth day of testing, Marko said: “What I saw yesterday on the circuit, Ferrari for sure is the fastest car.
“Behind that, it’s Red Bull and Mercedes. So let’s see what we can do, but at the moment we are quite optimistic we can win races from our own strength and not just if others have trouble, or at special circuits like Monte Carlo and Singapore.”
Red Bull-Honda relationship ‘very good’
Despite Red Bull not challenging the top of the timesheets during the first test, the team managed to complete an issue free test with the new Honda engine, so far proving to be reliable.
The team decided to switch from Renault power after a rocky relationship during the hybrid era.
Commenting on the new partnership with Honda, Marko added: “I mean, it’s a new period. We don't look back, we look forward. It’s a very good relationship [with Honda].
“The concern was, of course, reliability and so far there’s not a problem at all. It’s a new culture as well, but it fits well with our people.”
The second test of 2019 will begin next week, with teams likely to reveal more of their performance ahead of the first race in Melbourne.