The Croatia international managed only seven appearances in the Bundesliga after joining during the January transfer window on a deal until the end of the season.

Juve boss Massimiliano Allegri had hoped to see Pjaca return to Turin a rejuvenated figure, with the 23 year-old having missed much of 2017 with a cruciate ligament injury.

However, the winger admits he is unsure where he will be playing once Croatia's World Cup campaign comes to an end.

"The loan to Schalke didn't turn out to be what I wanted, but we can't change that now," Pjaca said. "I still don't know where I will play next season. A lot depends on the World Cup, too."

Pjaca joined Juve from Dinamo Zagreb for €23million in July 2016 and enjoyed a successful first season in Italy, winning the domestic double and helping his side reach the Champions League final before injury halted his progress.

Allegri confirmed he saw Pjaca in his long-term plans at the club before sanctioning his loan move.

"He is a boy who has extraordinary qualities and unfortunately this injury has temporarily stopped his progression," Allegri said. "So, he needs to find a team where he can find continuity to return next year in the best condition."