Philipp has been out of action since suffering serious kneecap damage in Dortmund's 1-1 draw with Bayer Leverkusen on 2 December 2017, while Schmelzer - having missed eight of 17 Hinrunde matches because of a recurring ankle problem - suffered a calf muscle strain during the recent winter break.
Both players were able to train individually with the ball, without any adverse effects.
*Translation: He's back! Maximilian Philipp is training with the ball!*
*Translation: Marcel Schmelzer also has the ball at his feet again!*
Dortmund, who could welcome back fit-again attacker Marco Reus when they host Hamburg on Saturday afternoon (kick-off: 15:30CET/14:30GMT), sit fourth in the current standings, occupying one of three automatic UEFA Champions League group stage qualifying places behind runaway leaders Bayern Munich.