If the Pirates can't reach a deal or find a suitable trade, it won't be as if they're hurting for bullpen arms heading into Spring Training. At this point, their bullpen will include Arquimedes Caminero, Neftali Feliz, Jared Hughes, Mark Melancon, Juan Nicasio and Watson, along with another pitcher from a group that includes John Holdzkom, Guido Knudson, Jorge Rondon and Rob Scahill, among others. They have a ton of options.
The Pirates typically don't use their relievers as specialists, so any left-handed addition would have to get out both righty and lefty hitters.