"He's not gonna be 100 percent," Carlesimo said during a Thursday interview on ESPN New York 98.7 FM "The Mike Lupica Show." "The reality is he's not gonna be 100 percent this year, and I think that's the thing that a lot of people are having difficult grasping.
"He's playing dinged up. His ankles are not good at all. And that wrist has been a problem for him all year."
Williams has been hampered by a slew of injuries in 2012-13 but has missed just three games. Prior to the season, he had a cortisone shot because of bone spurs in his left ankle and admitted that he would need offseason surgery to clean it out.
He missed two games before the All-Star break due to inflammation in both ankles. Williams underwent platelet-rich plasma therapy Feb. 11 and took a week off to rest. He has since returned and averaged 21.0 points and 8.5 assists in victories over the Milwaukee Bucks on Tuesday and Wednesday night.
Williams told reporters in Milwaukee after Wednesday's game that he was going to receive cortisone shots in both ankles Thursday but said he was fine and that the procedure was planned in advance.
Williams also missed the Dec. 26 loss in Milwaukee due to a bruised right wrist. He has also been bothered by quadriceps and shoulder discomfort this season.
The 28-year-old's numbers have been down across the board. He is averaging 16.9 points and 7.6 assists on 41.5 percent shooting. Williams has knocked down just 36.1 percent of his jump shots and is shooting just 31 percent in the fourth quarter, according to statistics obtained from basketball-reference.com. He has attempted just one dunk this season -- a miss -- because he has no explosion due to his ankle injuries.
Still, Carlesimo recently said he was "befuddled" by all the criticism his $98 million point guard was receiving.
"It's hard for me to overstate how much he brings to the table," said Carlesimo, whose team is 33-22 and 11 games over .500 for the first time in seven years. "... It would be scary to think of playing a game without Deron Williams."