VANCOUVER -- The Canucks aren't sure why yet. All they know Keith Ballard is out indefinitely.
The veteran defenseman missed the final two games of Vancouver's four-game road trip after a hit led to headaches -- and the possibility of a concussion -- and still wasn't back on the ice as the team prepared to host the Phoenix Coyotes on Monday night.
Coach Alain Vigneault said Ballard was still being evaluated.
"We're not sure if it's neck-related or concussion-related, so docs are checking into the neck and if that's causing the headaches that he has now and then, or if it's as simple as it being a concussion," Vigneault said. "He's out until we figure out exactly what we got."
The line between head and neck injuries -- and relationship between the two -- has been blurred of late, with news Pittsburgh star Sidney Crosby was suffering from a soft tissue injury in the neck, which could have masked themselves as the post-concussion symptoms first believed to have sidelined him.