How to fill the eighth-inning role?

Last night's trade that sent Tyler Clippard to the Athletics in exchange for Yunel Escobar probably was tough for a lot of people in the D.C. area to take. Clippard was beloved by many fans for his walk-out music, his pleasant nature and his consistency. He was highly regarded by those in the organization because of how genuine and stand-up he was, and his willingness to take the ball every single day if need be. He was greatly appreciated by reporters because of his honesty, patience and thoughtfulness. But now Clippard is gone from the organization with which he had spent the last seven years. And now the Nationals will need to figure out how to replace him. With Clippard out, Drew Storen now embedded as the closer and Rafael Soriano on the free agent market, the back-end of the Nats bullpen will look a lot different in 2015 than it did for much of 2014. But that said, there are still a number of relievers set to return this upcoming season. In addition to Storen, righties Aaron Barrett and Craig Stammen will be back, as will lefties Matt Thornton, Jerry Blevins and Xavier Cedeno. Blake Treinen could get more work in relief, and up-and-coming lefty Matt Grace could factor in, as well, after he was added to the 40-man roster this winter. The way I see it, Barrett and Treinen might end up being counted on in a major way this season. Barrett had a breakout rookie campaign last season, posting a 2.66 ERA with 49 strikeouts in 40 2/3 innings. He worked the full seventh inning in high-leverage spots at times last year, and could be called upon in that role more frequently in 2015. When Treinen was used out of the Nats bullpen last year, it was mostly as a multi-inning reliever, but he most definitely has the stuff to be a late-inning option called upon to get three big outs late in a game. As we've discussed before, some talent evaluators within the organization see Treinen as a potential closer down the road, and while the Nats could choose to still develop the righty as a starter (they also see him possibly becoming a solid major league starting pitcher), they might now prefer to use him as a big league reliever. One other in-house option to keep an eye on is righty A.J. Cole, viewed as the Nats' second- or third-best prospect by most scouts. Cole has strictly been a starter to this point in his pro career, but the Nats feel that he's big league-ready, and if they have a need in the bullpen, they could use his mid-to-upper 90s fastball and solid changeup and curveball in relief. One other thing that trading Clippard for Escobar does is that it likely frees up around $4 million of salary space for the 2015 season. The Nats could always choose to reinvest that money in the bullpen either with a free agent signing or another trade. Escobar can give the Nats a second baseman for 2015, he can bring insurance at short if Ian Desmond leaves via free agency after this season, and he provides a bridge to Trea Turner, the Nats' likely shortstop of the future. Escobar can't (to my knowledge, at least) work the eighth inning. With Clippard gone, those duties will have to fall to someone else this season.