Nick Kyrgios' injury frustration since his Australian Open heroics continue with the top seed withdrawing just hours before his opening singles match at the ATP Tour event in Florida.
"I'm dealing with a little bit of a left wrist injury; been dealing with it for the last week or so," Kyrgios said on Monday.
"Some sort of tendon thing. Apart from that feeling pretty good."
Kyrgios has not played since his fourth-round loss to then world No.1 Rafael Nadal at the Australian Open, which ended his crowd-pleasing home grand slam campaign.
Earlier this month, he pulled out of the New York Open because of a shoulder issue.
While he withdrew from his singles match against Tommy Paul at the Delray Beach Open, Kyrgios remained in the doubles draw.
His is scheduled to partner countryman Jordan Thompson, who retired after dropping the opening set 6-2 in his first-round match against Serbia's Miomir Kecmanovic.
The withdrawal of Kyrgios meant all four Australians at Delray Beach failed to progress beyond the opening round of the ATP 250 tournament.
Bernard Tomic, who entered the main draw as a lucky loser, saved 13 of 17 break points but eventually went down 6-2 3-6 6-2 to Germany's Cedrik-Marcel Stebe.
Fifth-seeded Aussie John Millman won the first set but suffered a three-set loss to Japan's Yoshihito Nishioka on Tuesday (AEDT).