It probably won't completely derail but it really knocks his chances of being a successful starter next season since he can't log 120+ innings next year. Would he have been in the big leagues next year as a starter? Does the MLB experience help him ease the transition from AAA to MLB as a starter? He likley wouldn't start this year with the Cubs. Could he in 2011? Probably. Can he Still? Probably. Does the MLB bullpen experience help him and the Cubs this year? YES. Good move all around actually. That's the point. He's not starting with the Cubs in 2010. If he starts with the team in 2011, he's never thrown more than 100 innings in a season; that's not going to cut it for someone in the rotation for a full season. You ask for anything more than a standard bump up of 20 innings and you're begging for major arm injuries. But it's ok, the Cubs like to do that with young aces. I understand that his arm is not conditioned for more than 120 innings but even he he got to that total this year, would you still expect 200 in 2011? Likely not. 150, more plausible. If he throws 80 this year, 120 next year is within the realm of possibility and that is a starter's load fora rookie pitcher anyhow. Like the Jabba rules right? I dont understand the big deal of pushing him up in MLB and only getting 80 innings this year. To me the 80 innings plus 4 months of MLB experience is better than 120 IP in Iowa. I think what the issue really is the Cubs history of arm injuries with these cases and not the inning totals. Obviously there are ways to condition an arm without having to throw innings. All MLB does it every spring.