Red Sox building a Royals-like bullpen with addition of Carson Smith

Are the Red Sox done dealing? (2:45)

Jim Bowden and Jerry Crasnick break down Boston's acquisition of Carson Smith from the Mariners for Wade Miley and if Boston team president Dave Dombrowski is done dealing this offseason. (2:45)

The trade: The Boston Red Sox send left-hander Wade Miley to the Seattle Mariners for pitchers Carson Smith and Roenis Elias. The Mariners also acquire minor league right-hander Jonathan Aro as part of the trade.

The signing of David Price left the Red Sox with plenty of options in the starting rotation, and they used that depth to improve their bullpen. After earlier acquiring Craig Kimbrel from the Padres, they've now added Smith, a right-hander who dominated in his first season in the majors, with a 2.31 ERA, 92 strikeouts in 70 innings and just two home runs. With a low arm slot and his fastball/slider combo, Smith gets a lot of movement and sink on his pitches and crushed right-handers, who hit just .169/.248/.254 against him; lefties weren't much better with a .227/.315/.273 line. He's not a big name, but he's very good.

Elias has started the past two seasons for the Mariners, but command issues mean he'll probably never develop into anything more than back-of-the-rotation starter. But his fastball/curveball/changeup repertoire means he could profile well in the bullpen, especially if his 91-92 mph fastball plays up in relief.

For the Mariners, they needed a starter after losing Hisashi Iwakuma to the Dodgers. Not trading him at the deadline now looks like a mistake, although they will receive a compensation pick for losing him. Miley is a durable lefty who has pitched 190-plus innings each of his four seasons in the majors, one of just 10 pitchers to reach that total each of the past four seasons. While he had a 4.46 ERA with the Red Sox, his FIP was 3.81, so his peripheral numbers suggest a better than the ERA suggest. The Mariners can hope for better production as he moves from some of the more hitter-friendly parks of the AL East to the pitcher-friendly parks of the AL West.

The reason: The Red Sox were 26th in the majors in bullpen ERA in 2015. Obviously, we've seen the success the Royals had with a dominant back of the bullpen, and that's what the Red Sox are going for with Kimbrel, Smith and Koji Uehara. The Red Sox still have Junichi Tazawa, and Joe Kelly could be a terrific reliever if he's not in the rotation. You can see the benefit of being a big-market club: Pay the money to get Price and then use your new depth to patch other holes. While Miley's reliability is a plus, the Red Sox still have Rick Porcello, Clay Buchholz, Eduardo Rodriguez, Kelly, Henry Owens, Brian Johnson and Steven Wright as starting options.

The Mariners arguably underestimated the market for Iwakuma, who has missed time the past two seasons, but with minor, non-arm injuries (finger, lat strain). Their rotation is now Felix Hernandez, Miley, Taijuan Walker, James Paxton and Nate Karns, with Vidal Nuno and Mike Montgomery as very shaky depth. Miley is under contract for three more years (including a 2018 club option) for about $27 million. If he can stay healthy and keep throwing 200 innings a year, the M's will be happy.

The impact: The Red Sox have to feel much better about their pitching staff. They have an ace. They have depth. They've improved the bullpen. Nice job, Dave Dombrowski, even if the price for Kimbrel was steep. Next up: Trade Hanley Ramirez and Pablo Sandoval! (We kid, we kid; good luck with that.)

Mariners general manager Jerry Dipoto had a pretty impossible task this offseason: Take a losing club with some big contracts (Felix, Robinson Cano, Kyle Seager), no depth and a terrible farm system and try and make it more competitive. He has reshuffled the roster, and I like what he has done considering the resources at hand, but let's be honest: Most of those are minor upgrades at best. And he still has work to do: The bullpen is a mess after Joaquin Benoit and Charlie Furbush, and the M's still need a first baseman. I think Dipoto will be trolling the waters for another reliever or two and then gamble on a low-cost first baseman.