The Socceroos starlet joined the Scottish giants on a two-year loan deal from Manchester City but failed to make manager Brendan Rodgers' final European cut on Wednesday (AEST).

With Arzani a recent arrival at the club, Davies acknowledged the 19-year-old's conditioning lagged behind the rest of the squad, who had been training prior to the conclusion of the 2018 FIFA World Cup.

Celtic leave Arzani out of Europa League squad

"Daniel is a young player, he is still adapting to the environment here," Davies said.

"He is two weeks into his training program here, which is, in normal terms, still early pre-season.

"He still has a way to go to get up to speed, but he has a two-year loan and we are going to support his development.

"His main priority is to build up his condition, he’s had half a development team game.

"The style we have is fast-paced and intense, so players have to be at that level."

With the former Melbourne City winger showing signs of promise in the aforementioned development match, he could force his way back into Rodgers' revised Europa League squad should the Hoops qualify for the round of 32.