All depends on your budget..
LB: Christian Gunter, Ricardo Rodriguez(Switzerland), Ylli Sallahi(Austria), Erik Durm, Maximilian Wittek
RB: Passlack available for under 1m at the start,
ST: David Selke, Donis Avdijaj
Look at Mitchell Weider on a free end of first season, Reinhold Yabo(CM), Hennings(ST), Timo Horn(GK), Hildebrand if you want a short term back up GK, Trochowski is a cheap attacking player, Fabian Schar Swiss CB available on a free generally end of 1st season.. Howedes at CB is available cheaply given his status and potential..
There are some exceptional young German CB's in game like Jonathan Tah, Niklas Sule, Niklas Stark, Ginter, look at Kirchhoff at end of first season from Bayern- he goes for less than 3m, Kempf, Geis, look at Selke(ST), Ron Robert Zieler(GK)..