I'd like to keep Hayden and Yedlin as well too, mind. The former because I think he'll mature into a decent player, maybe not a starter but a nice option to have, and Yedlin because he'd be a great backup full back to better quality counterpart.
I'd keep Lascelles, Merino and Yedlin. To be fair, we could keep a fair few from our side as back-ups though, if we have a good starting eleven. The only issue there will be that they're used to starting and will probably throw a fit from being relegated to the bench/being squad players.