The 44-year-old former Socceroo resigned from Wanderers on Sunday, to take up an opportunity with Turkish Super Lig club Karabukspor.

“I’m still wrestling with it now,” Popovic said when asked about his decision.

“I’ve got an uneasy feeling in my stomach. A lot of that might be starting this club from scratch.

“We didn’t have a boardroom or an office, knowing I played my part building this club for five years... It’s a tough one to leave.

“I came here for the right reasons as well. I was at Crystal Palace, I had a very good job.

“My instinct told me to come here and start something. My instinct again is telling me this is the right challenge.”

He conceded it was poor timing, with Wanderers’ first game against Perth Glory precisely a week away.

“This isn’t great timing,” he said.

“This has just come up last night and this morning. This isn’t something you plan for.

“It’s a change of management overseas and I’ve been given the opportunity to take on that role.

“It’s not planned and I understand the timing but it’s something I felt was an opportunity very difficult to turn down.”

Popovic has long held ambitions to coach in Europe, although he suggested previously reported offers from abroad were more speculation.

The ex-central defender’s new club are based in Karabuk, four hours east of Istanbul.

The side currently in the relegation zone after seven games of the Super Lig season, having lost their past four, having been promoted in 2015-16.

Karabukspor competed in Europe in 2014-15 and had spent most of their existence outside the top flight until the 1990s where they’ve since yoyoed between the top divisions.

“I want an opportunity to coach in Europe,” he said.

“This is an opening for me to be able to achieve that and have success in Turkey.

“It’s a big challenge there, the club is third from bottom. It’s different to what I had here. I came here with a blank canvas.

“I’m going there as a change of manager. There’s already a squad picked and they’ve already played seven games.

“I’ve always loved a challenge. I believe it’s a calculated risk. It’s one that I feel if I want an opportunity in Europe, it’s one I need to take.”