According to GazzaMercato, they have identified Brazilian international Gustavo as a good name to join their squad and will make a loan bid worth €2-3 million, with the right to purchase him outright for €20 million.
The 29-year-old joined Die Wolfe from fellow German side Bayern Munich in 2013, and has won both the DFB-Pokal and the DFL-Supercup with them.
He played 30 times in all competitions last season, scoring one goal and assisting three.