The Liverpool midfielder made a successful comeback from long-term injury this week after being ruled out since Australia's final group match at the World Cup in June last year.

The 28-year-old played over 35 minutes during Liverpool reserves' 3-1 victory against Everton at Wrexham's Racecourse Ground.

Kewell made an instant impact after just 10 minutes as the midfielder picked out team-mate Craig Lindfield to add the third from close range.

However, Australia manager Arnold is remaining cautious over Kewell's inclusion in the Socceroos Asian Cup squad.

"Physically, he looked fantastic," said Arnold. "Liverpool had made it clear they wouldn't let him back on the park until he matched all his old test results, and he looked as good as I've ever seen him.

"It was just great to see him back on the field. He moved around very well, and this was a big stepping stone for him.

"Harry's done a lot of work to get to this stage, now it's all about getting some match fitness under his belt.

"He's got some of the best people in sports science working with him at Liverpool, he's got (Socceroos physiotherapist) Les Gelis there as well, so it's looking positive. You could tell how excited Harry was to get through it unscathed."

But despite the encouraging return, Arnold remained cautious whether Kewell would be in contention for the Asian Cup Group A opener against Oman on July 8 in Bangkok.

Kewell will hope to play some part in Liverpool's final three games of the campaign, which include the Champions League final in Athens.

"Look, there's a lot of water to go under the bridge before then," added Arnold. "I don't know what Liverpool have in mind for him for the rest of the season, but the next three weeks will be crucial to see how he goes."