The promoted Bundesliga club signed Japan captain Maya Yoshida on Tuesday to strengthen the defence for the top-flight challenge.

The 33-year-old signed a one-year deal with the option of another season, Schalke said.

"Maya is a leader who will organise our game from the back. He can play as a left or right centre-back and his calm style of play will give us stability," Schalke coach Frank Kramer said.

Yoshida's arrival softens the blow of seeing Japan defensive midfielder Ko Itakura join league rival Borussia Monchengladbach on Saturday.

Itakura was outstanding for Schalke last season as he helped the team secure promotion back to the Bundesliga after one season in the second division.

But Schalke lacked the financial ability to make Itakura's loan move from Manchester City permanent, and Gladbach reportedly paid around 5 million euros ($A7.7m) for his transfer.

Yoshida played last season for Serie A team Sampdoria. He previously played for Southampton, Diutch club VVV-Venlo and Nagoya Grampus in Japan.

"Maya's footballing, physical and mental qualities will enable him to take on an important role in our team," Schalke sporting director Rouven Schroder said.

Yoshida has made 119 appearances for Japan since making his international debut in 2010.

Elsewhere Cologne have signed Armenia attacker Sargis Adamyan from Hoffenheim.

Adamyan, 29, has agreed a four-year contract.

Australian Associated Press