Obersteller, 18, moves to Wycombe after failing to break into the first team at Millwall, where he was released at the end of last season.

"Jack was released by Millwall, but that doesn't bother me," Wycombe boss Paul Lambert told his club's website.

"Sometimes in football you have to take a step backwards to go forwards and we hope that will be the case with him."

The defender is Lambert's eighth signing of the summer and arrives back at Adams Park after he trained with the Buckinghamshire side towards the end of last season.

"I want to stress that he's not yet ready for the first team, but we think he could be one for the future," Lambert added.