The starlet's former coach has recommended he stays put in Dortmund for the time being, claiming a Primera Liga move could be adverse to his career
Gundogan has been linked to Barcelona and Real Madrid of late, but Oenning - who oversaw the Germany international's development from 2009 to 2011 - believes a move to either of the Spanish powerhouses could only prove detrimental.
"In my eyes, a switch to Barcelona would come too early for him," the 47-year-old remarked to Bild. "He is barely 22. He can think about such a move again when he is 25 or 26.
"What is to come of him at Barca? The guys at Borussia really should light a candle everyday. There can be nothing better for this club than to play under [coach] Jurgen Klopp."
The midfielder has established himself as a mainstay for the German champions since his €5.5 million move to Signal Iduna Park, but Oenning claims he has not been surprised at the promise displayed by his former player.
"I told Ilkay after our first training session together that he would develop into a player with great potential," he revealed. "He just looked wide-eyed back at me then.
"The boy has everything, and is far from being at the end of his development at 22."