Haywood exited Game 2 against the Miami Heat early in the fourth quarter due to pain from a strained right hip flexor.
His participation in Saturday's practice was limited to spot shooting and free throws. He spent the rest of the session doing conditioning work in a pool and on an exercise bike.
"It's one of those things where we're just going to wait and see what the body says," said Haywood, who has averaged 3.3 points and 4.3 rebounds while serving as the second unit's defensive anchor during the playoffs. "I'm going to wake up in the morning and hopefully be miraculously healed. I'm just going to do everything they tell me to do to try to be ready."
If Haywood is not available, 24-year-old Ian Mahinmi might get his first significant minutes of the postseason. The Mavs' other option when starting big man Tyson Chandler rests is to use a smaller lineup with Shawn Marion as an undersized center with Dirk Nowitzki at power forward.
"We'll have Mahinmi ready," coach Rick Carlisle said, "or we can do some things with smaller lineups."
Haywood said he originally suffered the injury during a practice before the Mavs departed for Miami. It did not bother him during the Mavs' Game 1 loss, when Haywood had seven rebounds and three blocks in 14 minutes, but the hip acted up during Game 2.
Haywood got treatment on his hip during halftime and quickly realized at the beginning of the fourth quarter that he couldn't help the Mavericks. Within a minute, Haywood intentionally committed a foul so he could exit the game, then hobbled straight to the locker room.
"Every time I moved, it felt like something was popping," Haywood said. "I had to go sit down. I had to get out of there. I couldn't do anything at that point. I would have been hurting the team."
The hip bothers Haywood the most when he tries to sprint. That's especially concerning against a team that's as dangerous on the fast break as the Heat.
"Like if LeBron [James] took off and I was trying to catch him -- which might be hard to do anyway -- but if I were to really try to kick it into third gear, that's when you really feel it," Haywood said.
Tim MacMahon covers the Mavericks for ESPNDallas.com.