The Boston Red Sox made the first move to shore up their bullpen by acquiring closer Mark Melancon from the Houston Astros for shortstop Jed Lowrie and starting pitcher Kyle Weiland. With Jonathan Papelbon lost via free agency and setup man Daniel Bard potentially moving into the rotation, the Red Sox need alternatives for saves in the bullpen.

Melancon converted 20 of 25 saves opportunities in 2011 while posting a 2.78 ERA and 1.22 WHIP. Currently he would figure to close for the Red Sox in 2012, but the team is still pursuing other trade options and Bard could still end up as closer if the transition to the rotation does not go as planned. If I had to make a bet, I would predict that Melancon will not lead the Red Sox in saves in 2012.

For the Astros, Lowrie figures to move into the starting shortstop role and should be able to hit 15-20 home runs given 500 at bats over the course of a full season. His batting average is going to be the question until he can solve right-handed pitching, as he has hit just .214 in his career against them with eight home runs in 529 at bats. Compare that to the damage he has done against southpaws in 279 at bats where he has batted .326 with 11 long balls.

Weiland struggled in his first major league action in 2011, posting a 7.66 ERA and a 1.66 WHIP. A relief pitcher in college at Notre Dame, Weiland has moved up the ladder each season since he was a third round pick in 2008. He has a career 3.51 ERA in the minor leagues, but lik emost younger pitchers, he still needs work on his control with 3.4 walks per nine innings. Weiland will likely start the season in Triple-A unless the team moves Brett Myers or Wandy Rodriguez in a trade.

If Brandon Lyon is healthy, he will likely have first shot at closing with Melancon out of the picture. Lyon was 20-for-22 in save chances in 2010 and has converted 78 of 107 save opportunities in his career.