Novak Djokovic has withdrawn from Serbia's Davis Cup tie against Denmark because of a hamstring injury.
The 24-time Grand Slam champion was booed off court by some Australian Open fans last week when he retired with the issue after losing the first set of his semi-final against Alexander Zverev.
Djokovic, 37, later posted a photo of an MRI taken of his left hamstring with the caption: "Thought I'd leave this here for all the sports injury 'experts' out there."
Serbia are playing Denmark in a first-round qualifying tie, which starts on Friday.