Andre Schurrle wants to leave Chelsea for Wolfsburg, according to Sky sources.
The German World Cup winner, who joined Chelsea from Bayer Leverkusen in the summer of 2013, has been linked with a return to the Bundesliga since the transfer window opened earlier this month.
Chelsea manager Jose Mourinho said last week he expects to reach the end of the window with the same squad but admitted a departure is possible in the event of "a phenomenal offer and a player super keen of accepting the challenge".
Both those criteria could be fulfilled if Wolfsburg agree to pay the £22.5m-plus Chelsea want, and although there has been no formal offer to date we understand progress is being made.
Wolfsburg are currently second in the Bundesliga, and Schurrle sees the 2009 champions as Bayern Munich's likeliest challengers.
As many as five clubs are thought to be interested in the 24-year-old forward, who scored his fifth goal of the season at Swansea recently.
Chelsea, meanwhile, are understood to be negotiating a posible deal for Fiorentina attacker Juan Cuadrado.
The Colombia international has a £26.8m buyout clause and, according to sources, has made it clear he would like to move to Stamford Bridge.