"Whelan will not appeal, he does not believe in the Russian justice system. His exchange is being discussed now," the lawyer said.
Whelan's defence is not a party to the talks, the lawyer said.
"We know about the talks, everyone is talking about them unofficially but we do not participate in this," Zherebnkov said.
Whelan has not pleaded guilty. His defence claims he was a victim of a provocation.
The Federal Security service detained Whelan in late 2018. Full details of the case have not been officially disclosed.