Netball Australia announced on Tuesday that Alexander's contract would not be renewed after almost nine years in the role, with the search for a new coach starting next month.

With the Diamonds losing both their world title and Commonwealth Games crown in recent years contributing to Alexander's axing, McMahon said it was clear that losing was unacceptable in the role.

"I don't think you get much of a grace period when you take on a national role," McMahon told AAP.

"It's a team we all expect excellence and success from so they've probably got to be ready to hit the ground running."

With 118-Tests under her belt, McMahon turned her hand to coaching last season with the Melbourne Vixens.

Vixens head coach Simone McKinnis is considered one of the front-runners to fill the Diamonds vacancy although McMahon said she hadn't spoken to her colleague about her plans.

Collingwood's Jane Woodlands-Thompson, Firebirds coach Rosalee Jenke, former Test captain and current Fiji coach Vicki Wilson have also been mentioned while young coaches Briony Akle (Swifts) and Stacey Marinkovich (Fever) could be in the running.

"Simone plays her cards pretty close to her chest," McMahon said.

"Some coaches may not have considered it too closely yet because of what was in place, and they will now.

"I don't know who will put up their hand but I can't wait to see who's next in the job - I think it's a really exciting time for netball to take another jump forward."

McMahon, who played 118-Tests, said wasn't shocked Netball Australia went in a different direction.

She said the expansion of Super Netball to include many of the world's best players had contributed to Australia losing their international dominance.

And that was the bottom line.

"That has strengthened international netball and I think that's a really good thing, but one of the worrying things from the Diamonds' perspective is that you don't want losing tight games to become a trend and the reality is that is has started to," McMahon said.

"The bottom line is with the Australian Diamonds that we want that team to be successful so on the back of the two unsuccessful major tournaments, perhaps the writing was on the wall."

She praised Alexander for her endeavour to improve the high performance component of the role.

"Lisa brought a new way of looking at things and she certainly put her own stamp on it and she's has been incredibly valuable.

"She's really seen netball through some massive leaps in professionalism and she'd been leading the team that led the charge through that so she's really had a huge influence.

"She had a fantastic record if you take a couple of those losses out her legacy is going to be a great one for the Australian Diamonds."

Australian Associated Press