The 6-7 Johnson, who has averaged 14.4 points and more than five rebounds per contest this post-season, suffered a broken orbital bone in his left eye socket in a fall against Dallas in the conference semi-finals and has missed the first two games against the Spurs.
San Antonio leads the series, 2-0. Johnson will continue to wear a protective mask for protection.
"It'll be a challenge, but I don't think it will bother me none," Johnson told reporters. "This is all part of it -- me getting back out there."
"Hopefully he'll be ready to go," said Coach Mike D'Antoni.