After Bahrain, the AMR24 appeared benchmarked as the fifth fastest car in the leading group on race pace, finishing ninth and 10th.
Fernando Alonso subsequently finished fifth in Saudi Arabia and sixth on the road in Australia, prior to receiving a penalty.
In Japan, the Spaniard earned sixth after what he claimed to be one of the best five weekends of his career while team-mate Lance Stroll had a more difficult time, though the Canadian moved up from 16th on the grid to 12th at the flag, passing several cars along the way.
But Krack says that Alonso beating both Mercedes drivers fair and square at Suzuka was a further indication that the team is no longer at the back of the leading group on race pace.
“I think we can agree that we were not in no man's land and that is positive,” he said.
“Because here, with the high degradation and - you can pass, we have seen you can pass in incredible places, although I wasn't aware that you can pass through the Esses - but you see that with a large enough pace delta and tyre delta, you can do it if you're brave enough.
“But we did not seem to be in no-man's land. We seem to be in the pack. We were ahead of the Mercedes. So that is very encouraging.
Source: Autosport