Alex Rodriguez informed Yankees officials in Tampa yesterday he isn’t ready to begin a minor league rehab assignment because his surgically repaired hip isn’t up to the task, a source told The Post last night. This despite Rodriguez tweeting a day earlier that he had been cleared to play in games by Dr. Bryan Kelly, the surgeon who operated on him in January. The tweet infuriated general manager Brian Cashman. “He is not ready to play in games,’’ a person with knowledge of the conversation said. “He is worried about his health.’’ The source also said he has heard speculation Rodriguez could use the hip problem to retire. That would allow him to collect the $114 million owed to him. Should Rodriguez retire because of a medical problem, he would avoid a possible suspension by MLB in the Biogenesis mess. The Yankees would also be able to collect 80 percent of the $114 million from insurance. Rodriguez, who elicited an expletive in an outburst from Cashman with his tweet, spoke with Hal Steinbrenner yesterday at the Yankees’ minor league complex. While the language went from X-rated to G-rated, the message remained the same: You are an employee of the Yankees and there are guidelines. “Alex spoke today with our owner, Hal Steinbrenner, who was working out at the complex. Hal reiterated the way — he did it more professionally than maybe I did — about managing from the top down,’’ Cashman said.