Cologne announced over the weekend that they have signed Slawomir Peszko, while the arrival of Tomoaki Makino will be confirmed if the Japan international successfully completes a medical.
Poland international winger Peszko has agreed a deal until the end of the season as the Bundesliga relegation candidates attempt to improve their squad before returning from the winter break.
The 25-year-old has moved from Lech Poznan and joins former Bayern Munich goalkeeper Michael Rensing and Christian Eichner from Hoffenheim in switching to the RheinEnergieStadion.
Meanwhile, defender Makino will link up with Cologne after the Asia Cup in Qatar and he will then undergo a medical.
The 23-year-old, who has been playing for J-League side Sanfrecce Hiroshima, was omitted from Japan's squad for last summer's World Cup, but Cologne sporting director Volker Finke has been impressed.
He told the club's official website: "I've been observing the player for a long time and I'm convinced of his qualities."