Oddly enough, while Link's spent plenty of time with Donnie, he hasn't actually seen him really fight much yet.

So when he sees Donnie at the training dummy, he stops. Takes a few moments to watch. See what Donnie's capable of.

When the staff slips free, it rolls towards Link's feet. Picking it up, he holds it out towards Donnie - and pulls out a staff of his own from his korok-enchanted pack.

Perhaps Donnie would like an opponent? Although he might want to ignore the fact that Link's staff looks rather like a broom handle.