After 17 straight winning seasons, I've finally found myself in a fire sale. I've just traded one of my two best SP for a couple of good prospects. I need to call up a 5th SP from AAA; I have no interest in tanking, although obviously short-term my rotation will be worse. The two choices are a 21-year-old in his first season of AAA, who is still improving, although he's good enough to get by at the ML level, and a 29-year-old journeyman who isn't as good as the youngster, and will be stretched as a 5th starter in the majors, but who is reasonable enough that he's better than tanking.
The Pitching IQ for the pitching coaches at the two levels are ML: 89, AAA: 76.
Should I hold the young guy back until next season, to get an extra year of eligibility for him, or should I promote him, where he'll get better coaching and will pitch better than the journeyman?