Jude Bellingham, 19, joined Dortmund from childhood club Birmingham City in the summer of 2020 on a deal which runs until 2025.
Donyell Malen, Jude Bellingham and new signing Karim Adeyemi all scored in the first half for dominant Dortmund.
Haller was picked up by Dortmund officials after landing at the city's airport and taken for his medical.
Erling Haaland finalized his move to Manchester City from Borussia Dortmund for 60 million euros to seal his return to England, the country of his birth.
Karim Adeyemi completed his medical in Dortmund and signed a contract this afternoon which will keep him at the Bundesliga club until June 30, 2027.
Manchester City announced they had reached an agreement to sign star striker Erling Haaland from Borussia Dortmund -- sending an ominous statement of intent to their rivals.
The thumping win over mid-table Wolfsburg leaves second-placed Dortmund six points behind Bayern, who are away to Arminia Bielefeld on Sunday.
After back-to-back league defeats, Bayern leapt from sixth to second in the Bundesliga behind Borussia Dortmund who routed Stuttgart 4-0
Seri was swayed by the promise of regular first-team football and Chelsea's case was not helped by being still in a state of flux over the status of manager Antonio Conte.
There was near silence from the half-full south stand, which normally holds 24,500, as the club backed the supporters' silent protest.
Klopp says his current Liverpool squad is the strongest he has ever worked with as the players prepare for a return to action.
Having sealed his move to Arsenal, striker Pierre-Emerick Aubameyang has apologized to Borussia Dortmund fans for the breakdown in his relations with the German club.
The Bundesliga club also made what it called a "big concession" on the transfer fee to allow defender Marc Bartra to go to Real Betis.
Former Arsenal midfielder Tomáš Rosický on Wednesday announced his retirement from football at the age of 37.
The 28-year-old finished as the leading scorer in the Bundesliga last season with 31 goals, one ahead of Bayern Munich's Robert Lewandowski.
Dortmund travel to the Santiago Bernabeu for a dead rubber Champions League tie with holders Real already qualified for the last 16 while the Germans cannot advance.
Dortmund already have German World Cup winner Mario Goetze sidelined for the next six weeks with damaged ankle ligaments.
Since establishing a five-point lead at the top of the Bundesliga in September Dortmund have not won a league game.
Dortmund's second-half collapse saw them surrender a four-goal half-time lead to Schalke in the Ruhr derby on Saturday.
Dortmund desperately need a win at home to second-placed Schalke to break their negative run and relieve the pressure on Bosz.