A title-winner as Audi's factory team in 2017/18, Abt has struggled for performance and reliability on its comeback to Formula E as a Mahindra customer team, enduring a frustrating quartet of races across Mexico City, Diriyah and Hyderabad.
As the only team yet to score a point in FE's Gen3 era, Abt sits at the very bottom of the team standings going into this week's inaugural event in Cape Town, with an 11th place in India its best result so far.
While a lack of speed has been the main worry for Abt in the early part of the season, a number of technical issues have also proved to be a cause of concern, with substitute driver Kelvin van der Linde suffering two scary crashes across the Hyderabad weekend due to battery-related gremlins.
The team also had to retire van der Linde from the race on safety grounds.
But Muller feels that the problems Abt has faced in the early part of the campaign were "expected", given how late the squad was in finalising its Formula E programme after a season spent away from the championship in the wake of Audi's withdrawal.
He also expressed confidence that Abt will have a successful second half of the season once it has got on top of the issues that have plagued its return to FE so far.
"I have good hopes that we can have a very good second half of the season," Muller told Motorsport.com.
"[The first few races have] been difficult. A little bit as expected to be honest. We knew that the first half of the season was going to be a learning process with the limited testing we had and the complicated Valencia [test].
"So, I'm not surprised, but obviously still not very happy. We always want to fight at the front, that's our nature.
"Still, I think we are understanding more and more about the car, the directions we can take.
"We are exploring, we are still in a phase where we are taking very extreme steps in terms of set-up and software approach.
"We are just trying to gather more data, gather more information to have a clear direction to take for the future races. So, we will try to make steps but especially learn as much as possible."
Abt has several unused test days available that it can use to improve the Mahindra M9Electro package, which has shown midfield potential as best with the factory team since Lucas di Grassi's surprise pole/podium result in the season opener in Mexico.
But Muller explained that a packed first half of the year leaves little room for teams to complete in-season testing, with the first six races of the Gen3 era scheduled over a period of just two months from mid-January to mid-March.
"We do have some [test days available], but the problem is the schedule," Muller explained.
"The way it is at the moment there is not really any time to use them properly because you need time to analyse what has happened on the weekend, prepare for the next one and then to squeeze a test day in between is very tricky.
"So, for the moment we are focused on the racing, then we will see."
