The concern was that the 26-year-old might do more damage to an Achilles' problem, after Leeds sent a medical update to the Irish FA regarding his fitness.
Blackwell let out his anger on Northern Ireland boss Lawrie Sanchez regarding his handling of Healy in midweek. "We sent over the medical advice and he decided to ignore it," Blackwell said. "There will be a time when I shall repay that faith."