LaRoche and second baseman Freddy Sanchez did not play in the Pirates the 8-4 victory against the Colorado Rockies on Monday night at PNC Park, both were out with a back ailment. LaRoche has an unspecified injury in his back right rib area, and Sanchez has lower back stiffness.
LaRoche had been on a tear batting .390 in July, with home runs in his past three games.
Bixler, a shortstop, is the only infielder in the system that is already on the 40-man roster. He could take Sanchez's spot at second until he is ready to return. There are plenty of candidates to take over at first base in LaRoche's absence. Number one on that list is former Gold Glove winner Doug Mientkiewicz, Chris Gomez and Steve Pearce are also candidates for playing time.
Bixler was with the Pirates early this season when Jack Wilson was on the DL and struggled against Major League Pitching, but he has played well at Triple-A hitting .278 with six home runs in 58 games.