Wolfsburg have reinforced for their relegation battle by bringing in Turkey attacking midfielder Yunus Malli from Bundesliga rival Mainz.
ESPN FC's club correspondents run down the players at the biggest sides across the Premier League and Europe who could become free agents this summer.
Bayern Munich manager Carlo Ancelotti has said that Germany international Thomas Muller still has a place in his side.
"About Sevilla I have been told nothing. There is another offer, but for now I must continue with the German club," Vargas said.
Bayern Munich president Uli Hoeness has labelled the spending power of Chinese clubs "sick" after Pierre-Emerick Aubameyang was linked with a move.
Bayer Leverkusen sporting director Rudi Voller has said he would prefer Javier Hernandez to find form for the club rather than leave during January.