Speaking at his press conference on Friday, Kovač offered an encouraging update on his centre-back's recovery from the medial ankle ligament injury suffered at the World Cup.
"I hope that we'll have Nico back in full team training within the next week or two," Kovač said. "He would then be an option again."
Schlotterbeck sustained the injury in Germany's group-stage win over Ivory Coast on 20 June, an issue serious enough to end his tournament early and keep him out of Dortmund's entire pre-season, including their Supercup defeat to Bayern Munich.
Dortmund had been guarded about giving an exact timeline for his return, but the 26-year-old took a significant step forward on Wednesday when he began individual training with the ball for the first time since the injury.
His absence has been keenly felt at the back. Schlotterbeck was a key figure in a Dortmund defence that conceded fewer goals than any other side in the Bundesliga last season, contributing five league goals of his own — the joint-highest tally by any defender in the division alongside teammate Ramy Bensebaini.
He also finished the campaign with the second-highest number of duels won at the club, behind only Waldemar Anton.
Borussia Dortmund have had to cope without their defensive leader for the opening weeks of the new season, with captain Emre Can also unavailable through injury, and sporting director Ole Book has praised both players for staying heavily involved with the squad despite their enforced absences.
Kovač's side host Heidenheim in the Bundesliga this weekend and begin their Champions League campaign at Juventus on 16 September, a fixture that could yet come too soon for Schlotterbeck even under the most optimistic recovery timeline.
Schlotterbeck himself has been candid about the frustration of the recovery process, telling Sky in a recent interview that the initial injury felt manageable before proving far more stubborn than expected.
"At first, I thought it wasn't that bad and kept playing," he said. "We have to take it day by day.
"We're trying to let it heal properly and do good work with the physios and the rehab coaches. Then I believe it won't take much longer."
Dortmund added further defensive cover during the summer with the signing of 19-year-old French centre-back Joane Gadou from Salzburg, who has already started in the Bundesliga in Schlotterbeck's absence.