The 32-year-old, who was expected to stand in as Jimmy Howards backup, has been sidelined since March 14 with a partially herniated disc and has yet to fully recover.
Though he is expected to meet with team trainers in a few weeks, his lack of progress could push the Wings to deal with their goaltending situation.
"That's one of the issues we've been talking about," Holland said. "Health is a concern."
In 14 games with the Wings in which he took over for Ty Conklin as Howard's backup, MacDonald registered a .912 save percentage and 2.16 goals-against-average.
Meanwhile, Holland has no concern about forward Patrick Eaves, who sustained a broken jaw and a concussion in late November, and expects him to be ready for training camp.
As for veteran Tomas Holmstrom, who is scheduled to meet with Holland in the next week, he could choose to retire due to several past injuries and less playing minutes in the past seasons.
Defenseman Brad Stuart, who has expressed the desire to play out West to be with his family who resides in Northern California, Holland has mentioned that he will meet with the forward’s agent during the NHL Draft on June 22.