Pendlebury suffered the injury during the Magpies’ loss to Richmond last weekend and is struggling to overcome the issue.
Coach Nathan Buckley said he will miss Tuesday’s training session, but will be given until the last minute to prove his fitness.
“‘Pendles is a tough competitor,” Buckley said.
“He’s battling with that ankle injury but we’ll give him every chance.”
Meanwhile, young forward Darcy Moore is also in doubt due to a hamstring injury, which forced him to miss last week’s match.
But Buckley didn’t give anything away to reporters on Tuesday.
“He’s probably 51/49, and I won’t tell you which way,” Buckley said.