Renault have struggled for both performance and reliability over the opening rounds of the 2015 FIA Formula One World Championship, attracting criticism from both Red Bull and Marko, who labelled the team's early form a "catastrophe".
But with several changes to the power unit in the pipeline, Marko said dyno testing would reveal within weeks whether such struggles will continue - or whether Red Bull can enjoy the sort of competitiveness they demonstrated in Monaco, where Daniil Kvyat and Daniel Ricciardo finished fourth and fifth.
"We knew that the Monaco result did not reflect our real situation because in Monaco power is not that important," Marko told Formula1.com. "You saw it last weekend in Montreal: as soon as there is a long straight we lose out.
"We know that we have a handicap on the engine side, horsepower-wise. We are trying to adapt with really low downforce, low wing settings, but there is a limit to what you can achieve with that.
"Ferrari shows that it is possible to catch up in an ongoing season and Renault recognise now what they have to do. Development was obviously not going into the right direction.
"There are some steps coming, but we have to be patient. In three weeks from now we should know if the new project, which is on the dyno now, is working or not."
Marko added, however, that even if successful, Red Bull would not be able to adopt the new power unit until "at best the last three races" of 2015.
Look out tomorrow for the full interview with Marko, including his hopes for his home event in Austria, and his typically forthright views on how F1 racing is governed, and how he feels it should function in the future.