Red Sox acquire Melancon and Punto

The Red Sox, reinforcing their bullpen, acquired right-hander Mark Melancon from the Astros on Wednesday in exchange for infielder Jed Lowrie and right-hander Kyle Wieland.

To replace Lowrie, the Red Sox signed free-agent infielder Nick Punto to a two-year, $3 million contract, according to a major-league source. Punto’s deal includes roster bonuses that could increase his salary from $1.5 million to $1.75 million in each year of the deal, the source said. Marco Scutaro and Jose Iglesias are the Red Sox’s other alternatives at shortstop.

The addition of Melancon likely will be only one of multiple additions the Red Sox make to their bullpen. The team is talking to the Athletics about a trade for closer Andrew Bailey, and still could pursue free-agent closer Ryan Madson.

The Sox lost free-agent closer Jonathan Papelbon to the Phillies earlier this offseason, and are planning to move right-hander Daniel Bard from the bullpen to the rotation.

Melancon, 26, went 20-for-25 in save opportunities with a 2.78 ERA last season. He began his career with the Yankees.

The Astros plan to use Weiland as a starter and likely will make Lowrie their starting shortstop.

Lowrie is eligible for salary arbitration for the first time this offseason. Melancon becomes eligible in 2014 and Weiland in ’15, according to Cot’s Baseball Contracts.