Personally I wouldn't be too worried if you missed him but if hes on waivers and you've got someone cutable, I might just do it to be safe. This should have been in draft/keeper/waiver questions.
If you got an expendable kicker or defense, or anything you don't think someone will pick up than I would drop them and pick up Turner at least until the season starts, so you can make sure LT is healthy and ready to go, and then Turner will be expendable as long as theres absolutely no worries about LT (hammy injuries, turf toe anything) if there is worries, hold onto Turner and drop someone else if you need a D or K then.