Brisbane champ takes cortisone shot, requires rest for elbow injury.
The 31-year-old also won his first ATP win at Monte-Carlo in 2002.
Former world No. 1 now world influencer.
The Aussie seemed to escape injury on Sunday but apparently not all is well.
The American will have a little less spending money during his time in Europe this spring.
Five-time Grand Slam champion to make first grass-court appearance since 2015 Wimbledon.
Awaiting final decision on appeal of Sara Errani suspension.
