Miami - Novak Djokovic will try to win the Sony Open without his new coach Boris Becker, who is unable to travel because of surgery this week on both hips.
Becker planned to be at Key Biscayne before scheduling the surgery last week, Djokovic said on Thursday.
He said Becker hopes to resume travelling beginning with the Monte Carlo tournament, which starts on April 13.
"In these particular situations you can't do much about it," said Djokovic, who plays his opening match at Key Biscayne on Friday.
"If he has an operation on his hips, he cannot move, cannot walk, unfortunately. It has been something that has been an issue he has been carrying for many years."
The 46-year-old Becker, a six-time Grand Slam champion, joined Djokovic's team at the beginning of the year. Djokovic won his first title this year last week at Indian Wells.
"The benefits and the effects of our incorporation, Boris and mine, hopefully we will see in the rest of the season," Djokovic said.
Ranked No 2, Djokovic is a three-time Key Biscayne winner.