The 34-year-old was on course for a massive fourth-round upset on Monday until suffering a pectoral muscle injury early in the third set at the All England Club.
Dimitrov has now had to retire due to injury at each of the last five Grand Slams.
"Sometimes the heart wants to keep going... but the universe has a different plan for us," Dimitrov wrote in an Instagram post, which included a photo of himself in a hospital bed.
"Having to withdraw from this match at Wimbledon was one of the most painful moments of my career.
"Thank you for the overwhelming wave of love - from family, friends, fans, colleagues, to the entire tennis community... your messages have genuinely lifted me through these hard times.
"Thank you all. Truly. Recovery starts now. I'll see you all soon."
Dimitrov did not state the timeframe for his recovery, but reports suggest he is aiming to be fit for the US Open, which starts on August 24th.
Sinner has made the most of his reprieve, beating Ben Shelton in the last eight to set up a blockbuster semi-final against Novak Djokovic on Friday.