Brandt has confirmed that he will be leaving the Bundesliga outfit after seven years at Dortmund, which will leave a huge void in the attacking department.
The German international has contributed seven goals already this season as Dortmund sit second in the Bundesliga standings, nine points behind Bayern Munich.
Ricken said that Sancho, who is currently on loan at Aston Villa, could return for a third spell at the German club.
"We will need to replace Julian Brandt's creativity and goal contribution - we knew that when we made the decision," Ricken said.
"We are searching for an attacking player that will provide quality and can immediately help us, without spending enormous amounts of money.
"We are seeing who can make us better, and we are doing the same with Jadon."
The England international has already had two stints with BVB, featuring for the club between 2017 and 2021 and in the second half of the 2023-24 campaign while on loan from Manchester United.
Karim Adeyemi has seen his stock fall sharply during a turbulent season at Borussia Dortmund, with growing uncertainty now surrounding both his form and his long-term future at the club.
Karim Adeyemi has refused to be drawn on his long-term future after firing Borussia Dortmund to victory, insisting he remains focused only on his performances on the pitch.
Bayern Munich recovered from two goals down with three strikes after the 80th minute to claim a dramatic 3-2 win over SC Freiburg at Europa Park Stadion in the Bundesliga on Saturday.
Nico Schlotterbeck has dismissed reports suggesting he is close to signing a new contract with Borussia Dortmund, insisting talks remain unresolved despite growing speculation around his future.
