Mayer, a sporting industry veteran with more than 20 years of experience, replaces the long-serving Michael Petrillo, who has taken up a role with rivals Melbourne City.

Mayer has served as CEO of three different NRL clubs, most recently the Wests Tigers, while he has also held roles with AFL club Greater Western Sydney and English Super League team Catalans Dragons.

While it is Mayer's first role in football, he is clearly excited to begin after saying there here is "no reason" why the Reds can't be as big as the Adelaide Crows or Port Adelaide, two of the biggest clubs in the AFL in terms of memberships.

"The appeal to me is to help this game grow. I think there's so much upside in South Australia," Mayer said.

"In this town in particular, we're competing against two very strong clubs. For us, we need to reach that benchmark pretty quickly. There's no reason we can't do that.

"I look at this and think, there's 90,000-plus members in two AFL teams. We've got 9,500-10,000 members. We should be bigger than that."

Mayer said one of his first priorities when he officially starts in the role next week would be to meet with United's main supporter group, the Red Army.

"The fans have got to get behind this club and my job is to engage with as many stakeholders and members as possible very early to ensure we listen to what they want and respond accordingly," he said.

"People want to be engaged and I've got no problem with anyone who's got an issue with what's gone on before to get on the phone and come and see me."

Mayer said he already followed the A-League, but admitted he was a "boring bugger" who tracked off-field metrics such as broadcast ratings and crowds to benchmark clubs and sports against their competitors.

Adelaide United chairman Greg Griffin said he was "shocked" at the calibre of some of the 100 applicants for the job.

"What set Grant apart was he'd run successful, large clubs that did well on the field and under his tutelage off the field," Griffin said.

"The whole board met with Grant, he basically satisfied every concern we had and he was the standout candidate."