The Miami Heat and Oklahoma City Thunder have emerged as the early leaders in the race to sign veteran guard Derek Fisher after he clears waivers Wednesday, according to sources close to the situation.

With the Chicago Bulls needing another big man more than another guard and the San Antonio Spurs still hopeful they can complete the signing of guard Patrick Mills by week's end, sources told ESPN.com that Miami and Oklahoma City are the current front-runners to land Fisher, who was formally waived Monday night by the Houston Rockets.

The Heat explored the possibility of signing Fisher when he was a free agent in the summer of 2010 and have strong interest again now, sources say, even if they are successful in signing veteran forward Ronny Turiaf this week. Miami has only one open roster spot at present, but rookie shooting guard Terrel Harris hasn't played in six weeks and thus looms as a potential candidate to make way if the Heat need to make room for both Fisher and Turiaf, who was just waived by Denver.

Oklahoma City, meanwhile, is still trying to fill the void created by Eric Maynor's season-ending knee injury and, according to sources with knowledge of the Thunder's thinking, is intrigued by the prospect of adding Fisher's championship know-how to a group that's leading the Western Conference but still young.

It remains to be seen whether star forward Kevin Durant's recent decision to sign with Rob Pelinka as his new agent tips the scales, since Pelinka also represents Fisher. In addition, there is a feeling among some rival teams that the prospect of signing with a team in the West and having the chance to face the Lakers in the playoffs after his ouster is another factor that could help the Thunder in their pursuit of Fisher.

Sources say the thought of signing with the Bulls is something that strongly interests Fisher, but Chicago is well stocked at point guard and appears to be focused on trying to land Turiaf.

The Los Angeles Clippers, sources say, have likewise shown little interest in pursuing Fisher. That's even though the Clippers, like Miami and Oklahoma City, have a need for a playoff-tested guard after Chauncey Billups' season-ending Achilles tear and with Chris Paul carrying an increasingly heavy load.

The Spurs, by contrast, have long been fans of Fisher, sources said. But San Antonio, by all indications, is pressing ahead on the Mills front in hopes of completing its planned signing of the Australian point guard, who spent much of this season playing in China.

Fisher was officially placed on waivers at 6 p.m. ET Monday, giving teams under the salary cap 48 hours to claim him. He was owed a little less than $1 million for the rest of this season and had a player option worth $3.4 million for next season, but the Houston Chronicle reported earlier Monday that Fisher surrendered his entire 2012-13 salary to secure his buyout from the Rockets.

Players seeking buyouts must be waived by Friday to be eligible to play in the playoffs with another team.

Fisher's surrender of next season's $3.4 million marks the second time in his career that he has left a significant amount of money on the table to facilitate a move he wants. In 2007, Fisher gave up roughly $8 million owed by the Utah Jazz to return to the Los Angeles Lakers -- where he began his career alongside fellow rookie Kobe Bryant in 1996-97 -- so Fisher's family could be closer to the doctors who were treating his daughter for a rare form of eye cancer.