Plant doesn't ever get his feet set properly whenever he punches, he is always on his toes. He's hard to keep up with, but unless his stamina keeps up, which clearly he eventually will have a lull in activity Canelo would probably end up walking him down in the mid-late rounds after probably dropping the first 5 or 6 to him. Plant would easily be the quickest fighter Canelo has fought since Lara though, and Plant has fast twitch. He can trouble him, problem is can he actually outlast him. Canelo didn't show stamina issues in his last fight so I'm under the assumption that he may have worked it out.