Havertz suffered a muscular injury when he scored the winner in Bayern Leverkusen’s 1-0 win at Freiburg on May 29. The 20-year-old subsequently missed Saturday’s 4-2 home defeat to champions Bayern Munich.
Havertz has enjoyed yet another impressive campaign for Leverkusen, having found the back of the net 15 times in 38 appearances across all competitions.
The likes of Real Madrid, Bayern Munich, Manchester United and Liverpool have all been linked with the German international.
As Leverkusen bid to win only their second ever DFB-Pokal, and their first since 1993, manager Bosz has decided not to rush Havertz back into action, instead preferring to preserve him for this weekend’s Bundesliga clash with Schalke 04.
Asked about the 20-year-old's fitness, Bosz told a pre-match media conference: "The match is too early for him. He's not going to be in the squad.
"The question was if he's able to play. The answer is yes he would be able, but we would take a risk and we don't want to do that.
"We hope that he's getting better und be able to play [against Schalke] on Sunday. We have to wait."
Leverkusen are currently in fifth place on the Bundesliga table, but they are level on points with fourth-placed Borussia Monchengladbach.