Newly minted Astros general manager Jeff Luhnow made his first significant player move Wednesday, trading Boston for infielder Jed Lowrie and pitcher Kyle Weiland in exchange for reliever Mark Melancon.

To make room on the roster, Brian Bixler, whom the Astros claimed on waivers earlier this offseason, will be removed from the 40-man roster and is again available to any team.

The 27-year-old switch-hitting Lowrie has played sparingly for Boston over the last four seasons, hitting a combined .252 with a .324 on-base percentage and a .408 slugging percentage. He is considerably more proficient as a right handed hitter, with a .919 career on-base plus slugging compared to .635 as a lefty.

Weiland, 25, made his major league debut in 2011, amassing a 7.66 ERA in 24 2/3 innings. The 2008 third-round pick had a 3.51 ERA in the minor leagues with 3.4 walks and 8.5 strikeouts per 9 innings of work.

In giving up Melancon, the Astros flipped arguably their top relief pitcher whom they acquired in the Lance Berkman trade with the Yankees. The righthander took over the closer’s job from the injured Brandon Lyon last season.