Former NBA head coach Mike D'Antoni was in Houston this week interviewing for the Houston Rockets' vacant coaching position, ESPN.com has learned.

Sources told ESPN.com that D'Antoni, currently an associate head coach with the Philadelphia 76ers, spent Wednesday in Houston after the Rockets secured permission from the Sixers to speak with him.

The Rockets are just beginning what they intend to be a broad, deliberate search for a new head coach, not unlike the approach currently being taken by the Sacramento Kings.

Sources confirmed Wednesday to ESPN.com's Calvin Watkins that Rockets interim coach J.B. Bickerstaff has withdrawn from consideration after interviewing Monday with team officials. Bickerstaff posted a 37-34 record upon succeeding Kevin McHale and helped Houston rally into a playoff spot despite its season-long defensive struggles.

J.B. Bickerstaff went 37-34 after taking over for Kevin McHale in Houston this season. AP Photo/Brandon Dill

Sources say that former Rockets coach Jeff Van Gundy remains a candidate of prime interest, and Houston also is known to have strong interest in Indiana Pacers coach Frank Vogel if Vogel, as many around the league increasingly expect, is let go by the Pacers this week. The Rockets interviewed Vogel for the job in 2011 before ultimately hiring Kevin McHale.

The Rockets have already interviewed Los Angeles Clippers assistant coach Sam Cassell and current Houston assistant Chris Finch for the position, sources said, confirming an earlier report from The Vertical.

Sources tell ESPN.com that TNT's Kenny Smith, who like Cassell is a former Rockets player, could also land an interview. Rockets owner Leslie Alexander remains close to many players from the team's highly successful Clutch City era, which delivered two championships, and holds them in high esteem.

"I've always said anything basketball is me," Smith said Wednesday night on TNT when asked by Charles Barkley if he would be interested in the Rockets job. "And this is basketball. I enjoy being here. This is me."

Asked again by Barkley if he wanted to coach, Smith said, "Well, I told you if it's basketball, it's me. Under the right circumstances. I've been here 17 years, and I've enjoyed every minute of it."

The Rockets also are known to be intrigued by Texas' Shaka Smart and Kansas' Bill Self from the college ranks, but sources stressed Wednesday that Houston is focusing its search on proven NBA head coaches and rising assistants.

Bickerstaff withdrew his name from consideration when it became apparent that the Rockets were going in a different direction, but sources told Watkins that Houston has interest in retaining Bickerstaff in a front-office role.

Sources say, though, that Bickerstaff is expected to stay in coaching and pursue bench opportunities with other teams.

The Rockets fired McHale just 11 games into what was the first season of a new three-year deal. Houston ultimately lost to Golden State in five games in the first round of the playoffs, having slipped well off the standard it set in 2014-15, when the club won 56 games and reached the Western Conference finals.

The Rockets, Kings and New York Knicks are the only teams with head-coaching vacancies.