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. Source: ESPN