Around sixty pitchers on MLB 40-man rosters had the surgery in 2012 calendar year. Teams are anticipating elbow injuries and developing organizational procedures for dealing with this because they know it's going to happen. Look at Strasburg's famous shut-down. The Nats were fine with hard-and-fast rules on that because they'd tested the rules (to their satisfaction) with Zimmerman the previous year.

That fits the definition of "expected" to me.

But the larger point here is that pitchers get hurt. That's the most certain rule we have for this stuff.

Unless Sale does something truly unique to his arm, and perhaps even then, I don't think pointing to his visually gruesome mechanics is a fully satisfactory answer.

He's also in his second year as a full time starter and hasn't gotten hurt yet.