Sandro Wagner has joined Kaiserslautern on an 18-month loan deal from Werder Bremen, although he will not face his former side when the two sides meet on Saturday.
The 24-year-old, who made just eight appearances for Bremen in the first half of the season, has signed a contract with the Red Devils until June 2013 and becomes a Kaiserslautern player immediately.
However, he will have to wait before being able to make his debut.
"We agreed verbally with the Kaiserslautern management that Sandro will not play on Saturday," said Bremen's director of sport Klaus Allofs.
Bremen coach Thomas Schaaf welcomed the transfer, saying: "We have noticed that there was dissatisfaction both from him and from us.
"This transfer does not leave us in an emergency situation since we still have plenty of options in attack."
Kaiserslautern will have an option to make the move a permanent one at the end of his loan spell.
