Stoudemire was considered a game-time decision because of a laceration on his left hand. He suffered the cut after hitting the glass encasing of a fire extinguisher in frustration following the Knicks' road loss to the Heat in Game 2 on Monday night.
Stoudemire needed stitches to heal the wound and underwent a procedure to repair a small muscle on his hand the day after the incident, according to the team.
The nine-year veteran will play with protective padding around the cut.
"He'll be fine," Knicks interim coach Mike Woodson said before tipoff on Sunday. "If he gets hit on it and it opens up they've just got to stitch it up and keep moving. He's padded so he should be fine."
The Knicks trail the Heat 3-0 in the best-of-seven series. Woodson hopes that Stoudemire can provide a boost for the Knicks, who have struggled mightily on offense in the series.
"It's great that he's coming back. It's great for the fans to see him back on the floor," Woodson said. "And we've got to do everything we can today to try to get a win, that's what it's all about."
Baron Davis and Landry Fields will start in the Knicks' backcourt in Game 4. Carmelo Anthony will start at small forward, Stoudemire at power forward and Tyson Chandler at center for the Knicks, who lost Game 3, 87-70, with Stoudemire on the bench.
It's unclear just how effective Stoudemire can be with his non-shooting hand stitched and bandaged.
He practiced on Friday and Saturday and was cleared by team doctors to suit up on Sunday afternoon.
"They (the team doctors) thought it was OK for him (to play) and he wanted to play," Woodson said. "So I'm for it. He wants to put back on the uniform and get out there and try to help us win Game 4. I'm taking him in uniform."
Ian Begley is a regular contributor to ESPNNewYork.com.