Kewell had been expected to return for his second appearance of the season for the last-placed Heart but Aloisi ruled his former Socceroos team-mate out on Saturday morning.

It has been a frustrating time for the 35-year-old, who suffered a neck injury in the season opener against Melbourne Victory and twisted his ankle in training earlier this month just as he was set to return.

"He hasn't come through a training session as well as we would have liked," Aloisi told reporters on Saturday morning.

"There is no point risking him unless he is fit. There are still 20 games to go."

The Heart are searching for their first win of the A-League season having collected just two points in seven games.

Speculation over Aloisi's future continues to intensify, with former Heart coach John van 't Schip set to spend the coming weeks in Australia.

"It's always good to have another set of eyes and he is very experienced," Aloisi said when asked about van 't Schip's arrival.

Aloisi, who took over the coaching reins at the start of the 2012-13 A-League season after just one year as a National Youth League coach, remains confident he can turn things around.

"We can't let the outside pressure affect us," he said.

"There's always speculation but management have told me to just concentrate on my job.

"They haven't said to me 'John this is your last chance and you are out'."