Japanese midfielder Shinji Kagawa has been loaned out from German first-division side Dortmund to Turkish Super League club Besiktas for the remainder of the season, the two clubs said Thursday.

Kagawa underwent a physical in Istanbul earlier in the day, and said later on Twitter in German that he is "looking forward to a new challenge."

Turkish newspaper Hurriyet's online edition reported that Besiktas have agreed to a 1.6 million euro ($1.8 million) loan fee and the one-season deal includes a club option for a full transfer.

The attacking midfielder had only played in two league games for Dortmund this season.

He had been publicly seeking a transfer to Spain after being unable to beat out club captain Marco Reus, who has proven pivotal in the league-leading German side's pursuit of their first Bundesliga title in seven seasons.

Kagawa, who turns 30 in March, moved to Dortmund from J-League side Cerezo Osaka in July 2010 and contributed to back-to-back Bundesliga title runs. He spent two lackluster seasons with Manchester United before returning to Dortmund in 2014.

Besiktas is one of three big clubs based in Istanbul, alongside Super Lig rivals Fenerbahce and Galatasaray, where Japan defender Yuto Nagatomo plays. Besiktas are currently sixth in the 18-team top flight.