Neither player took part in Dortmund's full team training on Monday, but Kovac said there was no cause for concern over their fitness.
"That was completely normal today. It can happen from time to time that we let one or two players recover in the locker room or in the gym," Kovac said at his pre-match press conference.
"Both are in perfect health and are options for the game."
Dortmund will, however, be without Filippo Mane after the defender suffered a muscle injury during Saturday's 3-2 Bundesliga victory over Hoffenheim.
Kovac expects Mane to return after the upcoming international break.
"We're assuming nothing else will happen before the international break. He'll certainly return after that," the Dortmund coach said.
"Unfortunately, things like this are just part of the game. In terms of training load and training management, everything was top-notch; he had really good endurance and strength numbers."
Dortmund also have to cope without Nico Schlotterbeck and Ramy Bensebaini, who remain suspended despite making progress in their respective injury recoveries.
Giannis Konstantelias and Emre Can are also unavailable as they continue to recover from long-term injuries.
Bayern Munich are aiming high once again, with Konrad Laimer making it clear that the Champions League remains a major target as Vincent Kompany's side look to challenge for another trophy-filled season.
Paris Saint-Germain have already reached the top of European football. Now Luis Enrique and his players are chasing an achievement that would put them in truly historic company.
Matheus Nunes has declared himself fully fit and ready to play his part when Manchester City begin their Champions League campaign against Porto today.
Alexander Isak is enjoying his fast start at Liverpool and has called on the Reds to maintain their momentum after another important victory.
