Catch the high ball.
Once you've caught it, make sure you look up and see what's in front of you. Chances are you'll have a bit of time, so if something looks like it's on (and you've got support) run it back. If not, look for space and boot it clear/high.
In defence just hope it never gets to you... You're like the goalie, if something has gone wrong it's not your fault. That said, anticipate if someone's going to break, and act accordingly. Your job is to take the man with ball, if the support is behind them, let your teammates deal with it.