The first question that comes to mind is, what other OF'ers do you have?
Because this is a keeper league, I'm leaning that you take Hanley for Holliday and hold on to an elite SS.
That being said, if it's going to water you down at the OF position, that makes the move a little trickier.
Basically, if you have the depth at OF go for it. If not, you can work the draft for a servicable SS and hold on to an elite OF in Holliday.
One last thought. Both are suffering injuries... may want to weight those out as well being a keeper league.viewtopic.php?t=433369