Having taken the plunge of moving to the Bundesliga as a teenager in 2017, Sancho soon established himself as a starter in Dortmund.
He has since emerged as one of England's rising stars and is now valued at around £100m.
Sancho has attracted interest from some of the biggest clubs in football, including Manchester United, Real Madrid and Paris Saint-Germain.
However, according to the Daily Mail, events that have transpired this season have left Sancho disillusioned and unsettled.
Last month, Sancho was fined £86,000 by Dortmund for returning from international duty later than was agreed.
Dortmund went on to lose the game 4-0, but Lucien Favre's decision to hook Sancho so early was scrutinised.
"He was not injured, he trained yesterday," Favre told press after the game.
"I had to go on what I was seeing and, to be honest, it was not good enough."
The uncertainty surrounding the starlet's future has led to the likes of Real Madrid and Manchester United preparing proposals.
However, it's understood they will face serious competition from Premier League leaders Liverpool.
The Reds are running away at atop the table and may seek to consolidate their dominance with a stellar signing like Sancho.
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