David Cotterhill opened the scoring for Blues before Donaldson bagged a brace with the big striker trying to claim he touched in Cotterhill's effort and was claiming a hat-trick from the 3-1 win at the City Ground.
"He was trying to claim all three goals, but I don't think even Father Christmas would give him that," Rowett said after the game.
"I think all the players worked hard, but he has a difficult role up there, on his own.
"He plays it as well as anyone, because he is mobile, he has the size to win headers and he does get goals. He does everything well and, even if he does not score, he deserves his place in the team.
"We did have to defend well and our 'keeper (Darren Randolph) made a couple of good saves, but that is what they are there for.
"We were fortuitous to be 3-0 up at half-time, but I felt we earned a little luck," he added.
"We rode our luck a little bit, we dropped a little deep and let them get a few too many balls into the box, but I am not sure how many clear-cut chances they had in the game. We defended really, really well."