Filling in for the injured Yadier Molina, LaRue will start his third straight game for the first time since Sept. 1 of last year. LaRue is still fighting his right knee at times, which he had surgery on in 2006.
Manager Tony La Russa said without Molina, LaRue better be ready to go.
"He's going to have to be," La Russa said. "He's been waiting for this opportunity, so he's all excited."
Though the Cardinals don't necessarily expect LaRue to produce on the offensive end, any help couldn't hurt. Scoring has not come easy since Albert Pujols went on the disabled list and the Cardinals are in one of their worst slumps of the year.
As the numbers suggest, LaRue likely won't make an immediate impact at the plate. In 23 games, LaRue's batting average is .203 and he only has three extra base hits and four RBIs.
Molina, on the other hand, will fly with the team to Boston, but La Russa did not give a timetable on when the starting catcher will return.
"He's feeling better, but [Molina has not] been cleared yet to play," La Russa said.
Lee Hurwitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.