Galatasary are set to make a £2.5million (€3.5m) bid for Chelsea's Wallace, according to Fanatik.
The Blues wanted £5m (€7m) for the Brazilian defender but the Turkish club are said to have negotiated the price down.
The 21-year-old spent last season on loan with Dutch side Vitesse Arnhem and is being targeted to strengthen the right side of defence and midfield.
The Brazil U20 international is set to join the Istanbul giants who won the Super Lig for a record 20th time and have just booked their place in the Champions League group stages for a fourth season in a row.
Cimbom also recently signed Lukas Podolski on a three-year deal from Arsenal and former Reading midfielder Jem Karacan.
