MIAMI -- Free-agent guard Ray Allen will visit the NBA champion Miami Heat on Thursday, league sources confirmed to ESPN The Magazine's Chris Broussard.

Allen, one of Miami's top offseason targets, will also meet with the Los Angeles Clippers on Friday, the sources said.

NBA.com and The Associated Press had earlier reported Allen's planned visits.

Miami can offer Allen, who turns 37 this month and has spent the past five seasons with the Boston Celtics, only the mini mid-level exception, worth just over $3 million a year, while Boston is positioned to offer a two-year, $12 million contract, sources have told ESPN.com.

Celtics coach Doc Rivers talked to Allen on Sunday and called it a "stretch" that the NBA's all-time leading 3-point shooter will play elsewhere next season.

When asked about his status in a radio interview with "The Dan Patrick Show" on Tuesday, Rivers sounded much less confident.

"I don't know," Rivers said. "We're working hard. He has a lot of options and that's the bad news for us. It'll be interesting. I wish I had a feel on it. Usually I do. But I can tell you in this one I don't."

The Memphis Grizzlies have offered Allen their full mid-level exception, worth $5 million, for two years.

Like the Grizzlies, the Clippers can offer Allen the full mid-level exception. The Clippers view Allen as a starter, sources have told Broussard.

In addition to Boston, Miami, Memphis and the Clippers, the Minnesota Timberwolves, Atlanta Hawks and Dallas Mavericks have expressed interest in Allen, the sources said.

The Heat are also talking to free agent Rashard Lewis, who was recently waived by the New Orleans Hornets. The 6-foot-10 forward played in only 28 games last season because of a troublesome knee.