Plunge the depths of teams rosters for the next Street, Lidge or K-Rod. Most times these pitchers are learning how to pitch in the bigs WITHOUT assuming closing duties.
Yet, time moves fast in MLB and it's more likely than not that a Dotel or Percival-type will get hurt or play themselves out of a closing role. When it happens I find it best to ALREADY have their replacement on my bench, than worry about rushing to a computer to compete with rival owners on the ww.
You can NEVER have too many closers and in the event that the potential replacement is not going to get the opportunity to close you can just replace him via the wire like you would probably have done at some point with one of those 3 bench-warming starters.