Ange Postecoglou believes Harry Kewell brings an “energy and enthusiasm” that can help Celtic step up a level next season.

The former Oldham and Crawley boss was recruited to his fellow Australian’s backroom staff ahead of the 2022-23 campaign.

In Postecoglou’s first season at Parkhead he won the cinch Premiership title and Premier Sports Cup and he believes Kewell’s introduction can help with the desired improvement in a season which sees Celtic go straight into the Champions League.

Speaking to Sky Sports Scotland at Celtic’s training base in Austria, Postecoglou said: “I am always very conscious of making sure that every year we bring a freshness to everything we do, particularly with the players.

“We had a successful season last year but we know we have to go up a level this year.

“I think sometimes if players come in and see no change I don’t think it sends the right message.

“Harry has had a crack at trying to be a manager and he want to carve out a career for himself and he brings some real energy and enthusiasm for us.”

Christopher Jullien’s future at the club was also addressed by Postecoglou.

It was reported that the French defender was heading for a season-long loan at Schalke before the proposed deal collapsed.

Jullien played for most of Wednesday night’s friendly against Wiener Viktoria and also scored in the 7-0 win.

Postecoglou said: “Everyone’s future is the same. Everyone’s future is unknown. None of us have any certainty about what we do.

“With Christopher and the other lads, they are training with us and while they are with us I treat them as one of our players, and if that changes in the future it changes.

“The mood between me and him is the same as between me and Callum (McGregor, captain), there is no difference. He is a player at Celtic, I’m the manager and that doesn’t change with all the players.

“We had a similar situation last year with Ryan Christie, Odsonne Edouard, Kristoffer Ajer and I think if you speak to them, I didn’t treat them any differently.

“In terms of what we are trying to do and what we are planning for, we are still looking to bring in two or three players, there are still a couple of areas we need to strengthen in and we will do that.”

On defender Josip Juranovic, linked with Atletico Madrid recently, Postecoglou said: “He is part of the furniture here. He is training well.

“As I said, everyone’s future is uncertain.

“The key to it all is that whatever happens in the future is really determined by what happens today.

“With Josip and the other boys who had fantastic seasons last year, the key now is to improve this year and if they improve this year, all those things take care of themselves.”