The next couple months should tell a lot with him. If he's able to recover and pitch some near the end of the year or in the playoffs, even in a relief role, it'll help ease some concerns and he'll probably still go top ten. If it comes out he needs TJ, then he slides further.
And if he does fall to our pick, Id definitely take the gamble. I havent looked up what slot would be, but it would be tough for a kid to delay a million dollar bonus for three years, when there is a possibility he doesn't come back from the injury. Nick Adenhart(RIP) sign for like $750,000 when he slid from top ten status because of TJ surgery. Not saying Giolito would accept that amount, but if you're offering him $1-1.25 mill ... That'd be a hard thing for a kid to turn down while being injured. And rehabbing the injury under the eye of a professional training staff as your sole responsibility is a lot different than rehabbing in college while going to school. Definitely would be worth the gamble IMO.