Westwood was replaced at half-time at Plainmoor following what boss Steve Davis described as a "stamping incident" and left the ground on crutches.
The Railwaymen are hoping for a diagnosis of heavy bruising, leaving Westwood with a race to be fit for the final game of the season against Aldershot at Gresty Road where a point will be enough for the hosts to secure a play-off place.
"Ash's foot is very swollen after the stamping incident," Davis told Alex's official website.
"We are not sure of the extent of the damage and will send him for an X-ray.
"He struggled to get his boot on and it was obvious he couldn't play on, although knowing Westy he wanted to."