Yeah, I don't think the Celtics worked out Sully. I bet they didn't even inquire and if they had, his agent would've rejected it. The only other player I can recall Ainge taking without working the player out beforehand is Gerald Green who I think only worked out for the top 3 teams that year, which turned out to be a bad decision. Where the Celtics were at the time, there was no way Ainge could've passed on Green. His lack of ballhandling had to be a major draw too.
I'm not sure if Bradley worked out or if he couldn't because he had injured his ankle during a workout with OKC. He was planned for a workout anyway.
I'm just parsing post-draft comments but the workouts don't seem to be an insignificant factor either. Ainge seems to bring up what players did in the workouts every year. Kris Joseph apparently was one of the most impressive players in the workouts last year. Rondo's workout was supposedly legendary, so was Orien Greene's. Then again, Jefferson was said to have a bad workout, to the point that Ainge had to show Doc game footage immediately after so he could see that Jefferson was actually good. Since they ended up taking Jefferson, maybe workouts aren't too big of a deal, who knows. They still worked him out though so at least their interest was known.