Quintana and Teheran aren't even in the same conversation, and I would argue that Teheran has always been pretty worthless. -0.2, 0.2, 2.5, 3.2, 1.2, 3.2, -0.1 Those are his fWAR in his career. Combine his less than mediocre track record with his declining velocity and he's a hard pass. Those first two seasons have a combined 25 IP, they're irrelevant. He's also consistently outproduced his FIP, his full seasons by bWar are 3.2, 3.9, 1.5, and 4.8. His velocity hasn't declined. He's been a very good pitcher for a number of years, if you don't like him for whatever reason that's okay but if you're going to resort to histrionics like comparing him to Butler or saying he's 'always been pretty worthless' it undermines the point. If anything, now is the ideal time to explore trading for Teheran. His trade value is at its lowest, and he doesn't bear the weight of saving the rotation since they've already added Quintana. He's extremely durable(11th most IP since he entered the league, right with Hamels and Verlander) yet is still only 26 and you have him for 2.5 seasons.