A 4.56 era isn't what I would call having success. Lately marco has been what most would call terrible. The book seems to be out on marco. Don't swing at the changeup, wait for the meatball, and drive it. It took the league 4 years to figure him out? Did they figure him out the first part of last season and then lose the book on him? Isn't it more likely he is just going through a rough patch and will end up being who he always was? Yes, it is likely he will end up around the career 4.24 era. This is the only season he had been given a slot in the starting rotation for sure and was not injured for part of it. The league has obviously done more research and/ or he is declining. Whatever it is the simple truth is his ceiling is a #5 pitcher. Nelson's is clearly much higher. No reason to stay with estrada at this point