The deeper feeling that Fish had been somehow cheated continued to chew him up.

Marriage, fatherhood and financial security were not enough. So in December, Fish told his family and close friends that he had decided to rejoin the circuit.

“I was not secretive, but I kept it close to the vest for a while,” he said.

Fish has a protected ranking of No. 25, which means he can gain direct entry to as many as nine ATP Tour events (excluding wild cards) over the next 32 weeks. That would take him to Sept. 7, in time for one last stop at the United States Open.

He says he dreams of playing in New York, on the lawns of Wimbledon again or across the globe at the Australian Open, though such far-flung trips appear unrealistic.

Fish is still on anti-anxiety medication. He remains in therapy. He usually wears a heart-rate monitor when he practices. He has traveled outside the country only twice since competing at Wimbledon in 2012 — to Canada and the Bahamas.

But he is light-years from where he was. He can sleep alone. He has pushed himself in practice matches without incident. Last month, he flew cross-country by himself.

“It sounds crazy, but that’s actually a huge step for me,” Fish said.

His professional comeback will commence with baby steps. He has entered only the two Masters tournaments at Indian Wells and Key Biscayne, Fla., this month. Then he will reassess.