Borussia Dortmund have started their preparation for the second half of the Bundesliga season without seven players, including Mario Gotze, Raphael Guerreiro and Pierre-Emerick Aubameyang.
Dortmund returned to training with a performance test in one of the city's indoor facilities, but had to do without a host of key players.
Gotze did not take part in any of the sessions, which also included a lactate test as well as athletics and weight training. The Germany international returned from his winter break with an illness, Dortmund confirmed in a statement.
A quintet of players -- Guerreiro, Sokratis Papastathopoulos, Nuri Sahin, Neven Subotic and Sebastian Rode -- continued to work separately on their respective comebacks from injury, while Aubameyang was absent because of his involvement in the African Nations Cup in his native Gabon.
Dortmund are set to depart for their winter training camp in Marbella, Spain, on Thursday and will meet PSV Eindhoven in a friendly on Jan. 7.
Last season's Bundesliga runners-up currently sit sixth in the table following a largely disappointing first half of the season. They have picked up only seven wins from their first 16 matches and coach Thomas Tuchel has come under fire from parts of the media, with kicker providing an in-depth analysis of his 18-month tenure at the Westfalenstadion earlier this week.
Dortmund are expected to offload a few fringe players during the January transfer window. Mikel Merino has been linked with a loan move to another Bundesliga side, while Neven Subotic and Nuri Sahin have also been named as potential candidates to leave the club.
Adrian Ramos has been linked with a move to China, where Chongqing Lifan have reportedly offered him a three-year deal including a one-year loan stint with Spanish side Granada, who have a cooperation agreement with the Chinese Super League club.