The Warriors ruled out one of their valued subs because of left foot soreness at the morning shootaround before Game 4. Golden State leads the Western Conference finals 3-0.
"He's still sore," Warriors coach Steve Kerr said. "We got to make the wise decision here. This gives him a couple of days to prepare for a possible Game 5, and we just don't want to take a chance of harming his future availability."
If Dallas can stay alive by winning Game 4 on Tuesday, there will be a Game 5 in San Francisco on Thursday. However, if the Warriors can sweep the Mavericks, they and Porter will have over a week off before the NBA Finals are scheduled to start on June 2.
Porter left Game 3 midway through the second quarter and was later ruled out because of the soreness. X-rays were negative. The team listed him as questionable on Monday night's injury report.
Porter is averaging 5.5 points and 4.1 rebounds this postseason.
Otto Porter Jr. heads to locker room after injuring foot
Otto Porter Jr. injures his foot after going in for a layup and is forced to leave the game.