Williams was limited to three games in the NBA last season, all with the Oklahoma City Thunder. He split the rest of the season between the Thunder's NBA Development League affiliate in Tulsa and with the San Miguel Beermen of the Philippine Basketball Association, where he averaged 29.1 points, 9.2 rebounds and 5.3 assists.
The Heat have agreements with 16 players in place, heading into the start of training camp the final week of September, with teams allowed 20 players under contract during the offseason, a maximum of 15 during the regular season.
The Heat's current options behind Wade include Williams, Danny Granger, rookies Tyler Johnson and James Ennis, and point guard Mario Chalmers, who Heat President Pat Riley said is expected to see minutes this coming season at both backcourt positions.
Ray Allen, who served as Wade's primary backup at shooting guard last season, is weighing whether to return for a 19th NBA season, with that decision possibly to be deferred as late as September. The Cleveland Cavaliers are considered frontrunners for Allen's services should he return, with the Heat having already spent salary-cap space that otherwise could have been utilized on the NBA's all-time 3-point leader.