Pretty sure he'll clear waivers. There is a chance he gets the velocity back through mechanical adjustments and fixes his command issues. Of course he may just be losing some flexibility as he ages. I wouldn't close the door completely on him making it back.
I am a little surprised they did not just get Mercado, but Pinto is closer to mid-season form from winter leagues (Caribbean Series MVP) and is also stretched out if they need innings. Frankly they could use a middle man that can go multiple innings and they can just pick between him and Nelson when Kerkering makes it back. Covey does not look to be back any time soon.