Canelo has bad knees. He wears thermal tape on his elbows and knees. His joints have problems due to all the explosive training he does and weight lifting. Use it to your advantage. Don't let him stand still in front of his, keep moving, keep resetting him so you can see his attacks coming and prevent him cutting off the ring. If you square up and give him a 5 second window he will get power punches off. If Lomachenko was a little taller and 30lbs heavier he would run rings around Canelo.
People should keep in mind Plant is big, not too much smaller than Kovalev, not old or high mileage, and has lived a healthy life AFAIK. Not sure a KO for Canelo is too likely here. I think Plant will have a better showing than Smith but that fight might be the mold for this one.