Mats Hummels flattered to be attracting interest from across Europe but has no intention of leaving Borussia Dortmund.
If Danny Rowe departs Rotherham again this season it will only be to Wycombe, according to Millers boss Steve Evans.
The 32-year-old defender spent two years with the Spanish outfit, but saw out the latter part of last season on loan at Russian club Anzhi Makhachkala.
It was the Bosnian international's third spell in Russia, having previously played for Torpedo Moscow and Lokomotiv Moscow.
Bayer, third in last season's Bundesliga, have moved swiftly to add Spahic to their ranks.