Kyrgios delays comeback, risks rankings drop

Australian No.1 Nick Kyrgios risks losing his top-20 ranking after he was again forced to postpone his comeback due to an elbow injury.

Kyrgios suffered the problem during Australia's Davis Cup defeat to Germany three weeks ago and has since missed tournaments in Rotterdam and Delray Beach.

On Friday he pulled out of the upcoming Acapulco event featuring world No.2 Rafael Nadal and Australian Open runner-up Marin Cilic.

Kyrgios, currently ranked 15th in the world, reached the semi-finals at the tournament in 2017.

He will drop 270 points from last year -- the ATP's rankings are on a rolling 12-month schedule -- before he can next take the court at the Indian Wells Masters in early March.

The 22-year-old reached the quarter-final at that event 12 months ago and made it to the semis at the Miami Masters two weeks later.

If the elbow injury keeps him off the court and other players in the top 30 find some success, Kyrgios faces the prospect of tougher draws at the French Open and Wimbledon as a player seeded 17th to 32nd.

However, the Australian appears hopeful he will make an appearance in the coming weeks to defend his ranking points in the United States events.

"Getting closer, but still need a little more time to be able to play," he wrote on Instagram.

Meanwhile, Thanasi Kokkinakis will appear in Acapulco after receiving a wildcard into the tournament.

The oft-injured Australian this week made his return to the court after suffering a pec injury in the Australian Open.

He has won three consecutive matches to reach the semi-finals at an ATP Challenger tournament in Mexico.

Elsewhere, Jordan Thompson is into the semi-finals at a Challenger event in Japan, where John Millman and Blake Ellis are also into the quarter-finals.

Thompson won a title on the second-tier tour in Chennai last week.