The 19-year-old defender, currently on loan at the Bungesliga side, has impressed since joining and scored twice in a 5-1 victory over Werder Bremen on Friday as Gladbach climbed to fourth.
Schubert admits he would like the twice-capped Denmark international to remain at Borussia-Park in the long-term, yet acknowledges it is something that is ultimately out of his control.
"I would appreciate it if he would stay with Borussia for a very long time," he told reporters on Friday.
"He is a super defender and just a good footballer. This is a decision for Max Eberl [the club's director of sport], I can only express my wishes."
When asked about his future, Christensen himself remained coy.
He said: "I play as well as I can and see just what the future holds."
Christensen is currently on a two-season loan with the German side, although Chelsea have an option to re-call the player after a year should they see fit.