I'm not sure he'll have a innings limit, they plan to carefully monitor him and note any signs of fatigue.
Given he pitched 100 inning last year, is working out to build strength and stamina, they may just throw him as much as he can without showing fatigue, such as dropping his arm angle, etc. The smart thing is focusing on "tells" instead of velocity, since often pitchers subconsciously start to throw harder when velocity drop (which is why command often goes before velocity when a pitcher has a tired arm).