Gerald Schoenewolf, Ph.D writes for Yahoo regarding Michael Phelps relationship with his father.

Gerald Schoenewolf, Ph.D., is a licensed psychoanalyst in New York, an adjunct professor of psychology, and an author of 20 books of psychology, philosophy, fiction and poetry. He has also written and directed two feature films, the most recent being, BROOKLYN NIGHTS, based on the Dostoevsky short story, "White Nights."

He has written a article for Yahoo discussing Michael Phelps relation with his possible relationship with his father titled "Whatever happened to Michael Phelps Father?"

Granted, he acknowledges that his opinions are based on what he has seen, heard or read in the media but he makes a good case that not only did Michael Phelps over came adversity but that his father as distant as he may have been, has some rock solid integrity too.

From Yahoo:

None of them--neither the mother nor the two sisters--ever mention Michael's father. He has not been seen at the London Olympics, nor was he at the Beijing Games. It appears that Michael's father, Fred, is a persona non grata to this close-knit family comprised of mother, daughters and son. 

When Michael's father didn't attend the Beijing Games, Fred told told interviewers, "I'm very proud of him and all he's done. This is not about me, it's about him." Based on this one quote, he does not seem like an uncaring father. 

In an interview with Yahoo! reporter Summer Sanders following the winning of his 22nd gold medal (in case you have been living on Mars, he has won more medals at the Olympics than any other athlete), he spoke briefly about his relationship with his father. In a muted voice, when asked about his father, he said his father had come to the U.S. trials but not the Olympics. When asked about communication, he replied that there was "not much communication." When [Summer pressed him, he added, "We've been able to kind of talk. …"

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