Borussia Dortmund signed Serbian midfielder Milos Jojic from Partizan Belgrade on Friday, the last day of football's winter transfer window.
The 21-year-old Jojic signed a contract through June 2018 with the Bundesliga club.
''We are very pleased to have signed such a versatile midfielder with enormous potential to complete our squad,'' Dortmund sporting director Michael Zorc said.
Jojic has been the standout performer in the Serbian first division with six goals and seven assists in 15 games before the winter break.
He also scored on his Serbia debut in a friendly against Japan in October, his only international appearance to date.
Jojic provides Dortmund with another option following the season-ending injury to Poland midfielder Jakub Blaszczykowski and Germany midfielder Ilkay Gundogan's ongoing back problems.
Kicker reported a transfer fee in the region of 2 million euros ($2.7 million).
Also, Werder Bremen announced the transfer of French-Polish attacking midfielder Ludovic Obraniak from Ligue 1 side Girondins Bordeaux.
The 29-year-old Obraniak signed through June 2016 and said it was the ''right time'' to switch.
''For me it's a whole new step. I've only played in France up to now,'' said Obraniak, who previously played five seasons at Metz before switching to Lille in 2007. He helped Lille to the league and cup double in his first season and joined Bordeaux in January 2012.
The French-born Obraniak has made 32 appearances for Poland.
''I feel French but also have Polish blood. It's an honor to play for the Polish national team,'' Obraniak said at his Bremen presentation.
Croatian striker Srdjan Lakic returned to second-division Kaiserslautern on loan from Eintracht Frankfurt, where he was on loan to the end of the season from Wolfsburg.
Lakic previously played for Kaiserslautern from 2008-11.