Bayern Munich's France star Franck Ribery is an injury doubt for Friday's German league game against Cologne after picking up a thigh strain.
The 28-year-old suffered an injury in the 2-1 win over Stuttgart on Sunday which gave Bayern a three-point lead at the top of the table.
The Frenchman took a knock and had to be replaced in the 79th minute.
Bayern host Cologne at Munich's Allianz Arena on Friday in their final German league game of 2011 and Ribery will undergo further tests to clarify the extent of the injury after missing training on Monday.
"I gave a pass and fell something in my thigh," Ribery told Munich newspaper TZ.
Bayern are top of the league table with 34 points from 16 games and play their final game of the year at Bochum in the third round of the German Cup next Tuesday.