Liverpool midfielder Emre Can has suffered an injury scare while on duty with Germany at the Confederations Cup
Can is a doubt for the world champions' closing Group B match against Cameroon after withdrawing from Saturday's training session in Sochi.
Germany boss Joachim Low did not specify the precise nature of the injury, but described it as a "minor" problem sustained when the 23-year-old's "boot got stuck in the grass".
"During training, Emre Can has sustained a minor injury," Low told a pre-match new conference at Fisht Stadium.
"He bent over on the pitch. His boot got stuck in the grass. We will have to see how he feels because he had to break off training."
Low boasts a plethora of midfield options in an experimental squad and his side sit level on points with group leaders Chile following the sides' 1-1 draw in Kazan on Thursday.
He will rotate his line-up once more having already altered formations and personnel from the opening 3-2 win over Australia.
"Three or four changes are possible against Cameroon; seven or eight would be a bit exaggerated," Low explained ahead of his 150th match in charge of Die Mannschaft.
One confirmed alteration will be Roma defender Antonio Rudiger being restored to the starting XI, an attempt to nullify Cameroon's physical threat and pace on the break.
"Tony Rudiger will be back in the line-up because Cameroon has very quick players," Low said.
"He is a strong physical presence and is very quick. He will be able to counter the Cameroon players.
"This will probably be the match with the most legwork and the most taxing match. There is no other squad who likes more to go into the on-on-one situations in the competition.
"Look at the quick transitions they are able to enact and the pace of their attacking players. That is not a mix you often see over the 90 minutes of a match and Cameroon does have that."
One position where the selection merry-go-round might halt is in goal.
Regular No.1 Manuel Neuer is an injury absentee and Low rotated his goalkeeping options in the pre-tournament matches against Denmark and San Marino, where Paris Saint-Germain's Kevin Trapp and Barcelona's Marc-Andre ter Stegen started respectively.
Bernd Leno opened up with an error-strewn showing against Australia and, after Ter Stegen was restored to face Chile, Low suggested he could be ready to settle on one keeper for the remainder of the competition.
"This afternoon I will be looking into that with the goalkeeper coach Andy Kopke," he added. "We agreed that every player would have the opportunity to play during the preparation and the Confed Cup.
"We need to see how we will progress from here, whether we stick with that principle of rotation or stick with one goalkeeper for the last matches.
"That is something we need to decide with Andy Kopke."