Mardy Fish watched from afar as one side of the Wimbledon draw opened up. He couldn't help but wonder if he would have taken advantage to make a deep run.

Still, the American knew he made the right decision by delaying his return until he could enter a tournament at home in the United States and take the court in front of familiar faces.

Fish has played just one ATP Tour event since pulling out of the U.S. Open before his fourth-round match last September. Apologizing for his ongoing vagueness about the reasons, Fish again hinted Tuesday that many of his obstacles have been mental.

He missed about 2½ months earlier in 2012 because of an accelerated heartbeat, but Fish said the procedure he underwent in May of that year "gave us peace of mind that everything was OK."

"I'm trying to make sure mentally I'm where I want to be," he said on a conference call to promote this month's Citi Open in Washington, which he plans to make his second tournament back.

The 31-year-old Fish said he has worked closely with Jim Loehr, a performance psychologist who has counseled Jim Courier among other pro athletes.

"Some days are better than others," Fish said. "Some weeks are better than others."

The night after he lost at Key Biscayne in March 2012, Fish's heart started racing uncontrollably. That May, doctors induced extreme palpitations to try to pinpoint the problem. He returned for last year's Wimbledon.

His third-round victory in the U.S. Open went five sets, lasting more than 3 hours and ending after 1 a.m. Afterward, Fish did not attend the news conference, and tournament officials said he was receiving unspecified medical treatment.

The next day, he withdrew before his match against Roger Federer, saying it was for "precautionary measures" on doctor's advice. At the time, Fish expected to return to the tour quickly.

He didn't play again until Indian Wells in early March near his Los Angeles home, beating Bobby Reynolds in three sets in his first match back. Afterward, he talked about fighting "some demons."

"For the first three months after the U.S. Open, I had retired and non-retired in my head almost every week," he said that day. "And there was awhile where I was done."

Fish lost to a top-10 player, Jo-Wilfried Tsonga, in the next round in two tiebreakers. He originally planned to play Key Biscayne later that month but wound up skipping it.

Since then, his only tournament was a lower-tier Challenger event in Savannah, Ga., in late April, when he lost his first match to 103rd-ranked Ruben Ramirez Hidalgo in three sets. He described those forays as tests of where he stood in his comeback.

"Every move we've made has been very calculated," Fish said.

He has recently returned to the court with his World TeamTennis squad in Sacramento. He plans to enter the Atlanta Open, which starts July 22, then play in Washington a week later.

"I've turned the corner and been able to train as hard as I possibly can the last three months," Fish said.

Skipping Wimbledon was tough; he's always felt comfortable on those grass courts. And then it was frustrating to see all the upsets that might have given him a clear path to the late rounds.

But the Minnesota native wouldn't have had his full support system behind him in England.

"It was too far away, too soon," he said.

Fish, who reached a career-high No. 7 in 2011, tries not to worry about a ranking that has fallen to 61st in the world. He hopes his return will boost the floundering contingent of American men, none of whom reached the third round at Wimbledon.

"I know in the back of my mind that the tour's not going anywhere," Fish said. "The more time that goes by, the better I'll feel."

He can lean on the experience of successfully coming back from injuries in the past, and Fish even finds a positive in this absence. The last 10 months have put little wear and tear on his body, so perhaps that will lengthen his career. Fish optimistically mentioned Tommy Haas, who is ranked No. 11 at age 35 after missing significant stretches because of injuries.

Fish said he would eventually reveal more about his struggles, hoping to help others who have faced similar trials.

"I've done all the right things to put myself in position to come back," he said. "I'm ready to do it."