Adding Mark Melancon to the back end of the bullpen makes a lot of sense for the Nationals, given Jonathan Papelbon’s recent struggles. But doing it at the cost of Felipe Rivero, as well as prospect Taylor Hearn, makes a lot le s sense.Washington will have Melancon for two months, and he is unquestionably one of Victor Martinez Jersey the better closers in the game and a fine fallback option after the Nationals declined to meet the Yankees’ asking priceforAndrew Miller. The price the leaders of the National League East did pay, however, amounts to robbing Peter to pay Paul.MORE: MLB manager ratings Rivero’s ERA ballooned to 6.82for the season after adisaster of an outing on June 18 in San Diego, in which he allowed all six batters he faced to reach base on three hits, two walks (one intentional) and his own throwing error. In 13 outings since then, Rivero has re-established himself as a power arm out of the bullpen, with 15 strikeouts in 19.1 innings while posting a 0.93 ERA to get that season mark back down to 4.53.Rivero is 25 years old, a left-hander who excels at getting out right-handed batters, and has five years of team control left after this season. By FanGraphs’ measure of wins above replacement which uses FIP https://www.tigersedges.com/detroit-tigers/kirk-gibson-jersey rather than ERA, and thus can be more useful for looking forward than Baseball Reference’s ERA-based measure Rivero has been worth one-fifth of a win le s than Melancon over the first four months of this season. Had the Nationals’ trade been to acquire Melancon and add him to a bullpen mix with Rivero, it would have been much better for Washington’s relief setup for the rest of this season as well as for the Rivero-having future.Instead, it’s the Pirates who have Rivero to go with Tony Watson and Neftali Feliz in their bullpen, plus another hard-throwing southpaw in Hearn, who has 31 strikeouts in 22.2 innings in Single-A in his first full profe sional season. The Nationals drafted Hearn in the fifth round last summer. It’s easy to see why Pittsburgh, still very much in https://www.tigersedges.com/detroit-tigers/victor-martinez-jersey the mix for the wild card, would make this deal.MORE: MLB trade season is here; now the fun begins For the Nationals, it’s easy to see in the headline of adding Melancon, but while one part of Washington’s bullpen is unquestionably better, the cost of a productive bullpen piece from the current roster makes it a lot harder to justify.