Germany international arrived only at Stamford Bridge from RB Leipzig last July and were familiar with the Blues during the 2020-21 season, making 52 appearances in all competitions last season.
Werner scored 12 goals and provided 15 assists in his first season with Blues but managed to find the net 6 goals in the Premier League.
Chelsea are said to be keen to sign a new signing this summer, with Bayern Munich’s Robert Lewandowski and Borussia Dortmund’s Erling Haaland linked with action, which could force the former Stuttgart champion.
According to the Sky Deutschland, Chelsea have been in contact with a number of leading European clubs to find out if they would like to sign the 25-year-old.
Timo Werner, who has 4 years left to start his contract at Stamford Bridge, has scored 95 goals and provided 40 assists in 159 games he played in RB Leipzig before arriving in London.
