NEW YORK (AP) -- Patrick McEnroe announced his resignation Wednesday after 6 1/2 years as the U.S. Tennis Association's general manager of player development.

In May, the USTA announced plans for a $60 million tennis center in the Lake Nona area of Orlando, Florida, and McEnroe said that, for personal and professional reasons, he did not want to be based there full-time. He is also a TV analyst.

McEnroe will stay on with the group to help with the transition to a successor, a process that USTA Executive Director and COO Gordon Smith said could take at least four to six months.

McEnroe's departure, discussed at a news conference at the U.S. Open, comes during a tournament in which zero American men reached the round of 16 for the second year in a row — something that, until 2013, had never happened at an event that began in 1881.

No U.S. man has reached the quarterfinals at any Grand Slam tournament since 2012, and none has won a major championship since Andy Roddick at Flushing Meadows in 2003.

"Obviously, the world has caught up to us," McEnroe said.

Smith said the change was not prompted by recent results at the elite level, particularly on the men's side.

"If you look at where we are and where we have come from ... we have a great foundation. Frankly, I think we are going to see results of that," Smith said.

"Make no mistake, we're going to continue the course," he said.

McEnroe is a former professional tennis player and U.S. Davis Cup captain — and the younger brother of seven-time major champion John.

"It's very difficult to create top-level players," McEnroe said at the news conference. "I think I have a newfound respect for what my parents did to create two players, one who was really good and another who was pretty good."

When he was appointed to the GM post, the USTA said its goal was to bring together teenagers from around the country in hopes of maximizing their potential. In 2012, USTA player development set up five regional training centers, raising to 24 the total number of facilities in the program.

"We hired him for a pretty narrow job there. It was elite player development. It was just about a very few players," Smith said. "Patrick realized that the United States really needed a broad-based, organized regional and national program.

"So now we are in such a different place because of what Patrick has done, what he's brought to this country in terms of player development."