Askew joined the team this season having spent 2021 resigned to making occasional cameos in IndyCar at both Ed Carpenter Racing and Arrow McLaren SP as a substitute for the injury-hit Rinus VeeKay and Felix Rosenqvist.
Although the American driver - the first driver in the series from the US since Scott Speed in 2014-15 - scored two points in his first race at the Diriyah season opener, results have been harder to come by since.
The Floridian is hence under pressure to retain his seat, although had shown improved performance in qualifying at Marrakech where he made the duels for the first time.
Andretti said that he was delighted to be able to keep Dennis on board, but that the team was "working on" filling the second seat if Askew cannot continue to improve.
"We're working on the second [seat] - we don't know what we're gonna do yet," Andretti told Autosport ahead of this weekend's New York round.
"Frustrating year for him, I think we were all expecting a little more. I mean, especially because I know he's a really smart kid.
"He drove for us in Indy Lights and won the championship there, and he was very quick in IndyCar.
"I think he's just been having a problem with this tyre and getting dialled in, especially for qualifying because in a race, his pace is good.
"He always goes forward, but it's qualifying where he's at his frustrations. And I think it's just that he hasn't been able to get the tyre in the right window when he starts the lap.
"Last race, he qualified a lot better. So I'm hoping that he's getting a better feel for it."
Andretti admitted that the team's season had been frustrating following the departure of factory support from BMW, and that it was essentially working with the same baseline that it had at the end of last season.
However, he praised Dennis' performance for working with what the Andretti team has been able to provide before beginning its partnership with Porsche in Formula E's Gen3 era.
"We've gotten some results, but you know, I think it's been frustrating, because we're not developing," he explained.
"We're pretty much standstill from what we had the first race, actually the last race and last year, is what we have right now.
"Our competition has come a long way in terms of developing their power units. So, you know, as the year goes on, it's getting tougher and tougher for us.
"But we understand this transitional year. And, you know, we're really looking forward to our partnership with Porsche.
"Jake's done a great job for us, he's doing the best with what he has, especially with qualifying.
"And the race is where we really seem to suffer the most because we just can't save our energy the way the others can.
"But he's done a great job doing what he has, and we're happy that he's still going to stay a part of us."
