McDonald told the Sunday Herald Sun that Robbie Tarrant, returning from a shoulder reconstruction, was the only player in rehab at the club.
"(Tarrant's) out of a sling and won't be available for any NAB Cup games, but he's coming along well," McDonald said.
"He needs to get himself fit but all the guys who had surgery are back."
McDonald said players were impressive out on the training track this year, especially the leadership group.
"Brent Harvey, Drew Petrie, Brady Rawlings and Daniel Pratt have been leading from the front," McDonald said.
"We're hoping for big things from Nathan Grima, Michael Wundke and Josh Smith.
"And we need an increased output from David Hale, Aaron Edwards, Corey Jones, Matt Campbell and Lindsay Thomas.
"It's the third pre-season we've done under the conditioning regime of Paul Turk and we're hoping the guys in their third and fourth years really benefit."
