The 25-year-old Denmark international has joined the Bundesliga outfit on loan from OGC Nice until the end of the season.
Dolberg spent the first half of the season on loan at La Liga club Sevilla, where he made four league appearances and made one assist.
"We knew since the summer that we were still missing one component. Someone who has the right stature and can be a target player," Breitenreiter told Kicker.
"Apart from Munas Dabbur, we didn't have anyone who could secure balls with his back to goal.
"And we needed someone who has already proven that he can score goals. Kasper has great potential."
Hoffenheim's Bundesliga campaign resumes on Saturday when they travel to Union Berlin.