The Heat's highest-paid player questioned why the team is matching up when "we've got one of the best centers in the league."
"A lot of teams don't have a good center," Whiteside said. "They are going to use their strengths. It's bulls---. It's really bulls---, man. There are a lot of teams that can use a center."
Playing in his second game back after a nine-game absence because of what was described as left hip pain, Whiteside finished with 14 points, six rebounds and two blocks. Heat coach Erik Spoelstra spoke to reporters prior to Whiteside's tirade and said the center is rebuilding his stamina.
Whiteside, for his part, seemed uncertain as to whether the coaches have him on a minutes restriction, noting, "The minutes have been like that all year. It's really frustrating. ... It's tough. I don't know, man. It's crazy. I don't understand it."
Whiteside, who has missed 29 games this season due to injury, has seen his playing time average decrease to 25 minutes in 2017-18, down from 29.1 minutes in 2016-17, when he finished as the league's leading rebounder. The previous two seasons, he averaged 32.6 minutes.
Asked if the situation has caused him to contemplate his future in Miami, Whiteside replied, "I don't know. Maybe."
Whiteside, 28, has two years remaining on a four-year, $98 million deal.
The Associated Press contributed to this report.