A former Australian women's soccer international player has been jailed for eight and a half years for stabbing a friend in Adelaide on New Year's Eve.

Diana Patricia Hall, 56, played four times for the Matildas in 1979 and 1980 but gave up the sport when she became pregnant with her first child.

She pleaded guilty in the Adelaide District Court to an aggravated charge of causing serious harm relating to the stabbing of a man she had known for over 20 years.

Judge Simon Stretton said the pair had a "periodically tempestuous" relationship but kept returning to each other's company because of alcohol abuse and loneliness.

The court was told the man was not happy with the eulogy Hall delivered at a friend's funeral and that built upon other anger she had with him, to the point where she told others she planned to stab him and kill him.

After the funeral and while drunk, Hall grabbed a large kitchen knife and tucked it into her pants.

The court heard she walked to the man's house where she confronted and stabbed him seven times.

The man told police he thought Hall had been coming over for a New Year's drink and was shocked to see the knife.

He ended up with life-threatening injuries which required him being placed into an induced coma and needing several major surgeries.

Attacker came home covered in blood, drank champagne

The court heard Hall returned home covered in blood and told a friend what she had done, then finished half a bottle of champagne before police arrived and arrested her.

Judge Simon Stretton said she had been in custody since and he would take that, and her early guilty plea into consideration.

"It was a vicious and to some extent premeditated attack on an old man," Judge Stretton said.

"He could well have died, with you facing a murder or manslaughter charge."

Judge Stretton sentenced Hall to eight years and six months in prison with a five-year non-parole period.

He said the crime was too serious to consider suspending the sentence.