Felix Magath, the former Wolfsburg manager, has told the German club that signing Andre Schurrle would be a huge statement of intent.
Schurrle has found it difficult to break into the first team at Chelsea, having only started five games in the Premier League all season, despite playing a pivotal role in Germany's World Cup win last summer.
That situation is unlikely to change with Juan Cuadrado and Douglas Costa expected to be players at Stamford Bridge by the close of the transfer window on February 2.
Magath should show the same intent to sign Schurrle as when they lured Kevin De Bruyne away from Chelsea for £18m one year ago.
"With a transfer as huge as a Schurrle you could send out a signal to the competitors," he told Goal.com.
He added: "The rumours are circulating for a while now and the timing now is just right. I am confident they can become a serious rival for Bayern [Munich] in the long-term.
"With Kevin De Bruyne they already have an exceptional player from Chelsea. If Schurrle really joined, the squad's quality would rise again and they would increase their chances on a sporting level."
