A decision had yet not been made on whether LaRue would be placed on the 15-day disabled list.
"Until we know the extent of the tear, it's too early to speculate," Reds general manager Wayne Krivsky said. "But with a week to go until the season, we'll have to wait and see."
LaRue was catching a simulated game for Paul Wilson on Sunday when he felt pain while crouching behind the plate that forced him to walk off the field. An MRI exam confirmed the tear, Krivsky said.
"The sooner we do [the surgery], the sooner he'll be back," Krivsky added.
In 16 games this spring, LaRue was batting .167 (6-for-36). He hit a home run in Saturday's game against the Twins. Last season, the 32-year-old batted a career-best .260 with 14 home runs and set another personal best with 60 RBIs. He signed a two-year, $9.1 million contract in December.
With LaRue out, backup Javier Valentin will see more action. LaRue's situation could temporarily alleviate a roster crunch at catcher. The Reds acquired defensive specialist David Ross in a trade from the Padres last week, and they also have Dane Sardinha. Both Ross and Sardinha are out of options.
Ross' acquisition created speculation that either LaRue or Valentin might be on the trading block in a Reds' effort to acquire more pitching.
So far, the Reds are satisfied this spring with Wilson's rehabilitation from shoulder surgery.
But there seems to be a ways to go still before the right-hander will work from mound again in a Major League game.
Wilson, who has yet to pitch in an exhibition game this spring, threw 60 pitches on Sunday morning in his simulated game to Minor League hitters. Reporting no pain, he is scheduled to throw on the side on Tuesday before working another simulated game on Friday.
As expected, Wilson will remain in Florida to continue his throwing program in after the Reds head north to begin the regular season.
"We're going to leave him down here to work in extended spring training for at least the first couple of weeks of April," Reds head trainer Mark Mann said. "Depending on his progress those first two weeks of April, we'll determine what the next step is for him."
An eventual step for Wilson before returning to Cincinnati would be going on a Minor League rehabilitation assignment to start in some games.
The Reds prepared for this contingency throughout camp. Young pitchers, including Michael Gosling and Justin Germano, were originally auditioned to take the fifth starter's role. Then last Monday, the rotation was shored up with the acquisition of Bronson Arroyo in the trade that sent outfielder Wily Mo Pena to Boston.
Wilson had season-ending surgery last June to repair a torn rotator cuff and frayed labrum. The 33-year-old is in the final year of a two-year, $8.2 million contract that carries a 2007 club option.
During Sunday's throwing session, Wilson continued to throw fastballs and sinker pitches and used a curveball for the first time. He has yet to use a slider, a pitch that puts the most stress on an arm.
"For a guy that had surgery the middle of last season to be able to go out and compete in a live batting practice session to hitters," Mann said. "At this point, we're very pleased with his progress. He's incorporating his pitches more and more in these sessions."
Also on the rehabilitation front, pitcher Grant Balfour has increased to long tossing at distances up to 120 feet. The right-hander, who is recovering from both Tommy John surgery on his elbow and an operation on his shoulder, was signed in the offseason as a free agent.
Balfour isn't expected to be seen in a Major League game until sometime this summer. The pitcher hoped to begin throwing off a mound again for the first time next week.
Wagner looking good:
Trying to secure a spot in the Reds bullpen this spring, Ryan Wagner has put himself in decent position to make the team this spring. After a rough first outing early on, Wagner has since posted a 1.00 ERA over his last nine games (one earned run in nine innings).
Overall, the right-hander is 2-1 with a 3.60 ERA and two saves in 10 innings over 10 games. Coaches have encouraged Wagner to focus on his strengths of throwing two-seam fastballs and sinkerballs instead of sliders.
"The last couple of years, if he ever got a swing and a miss on a slider, you could flat out believe the next pitch would be a slider," Reds manager Jerry Narron said. "That's something he needs to get away from."
Wagner, 23, was 3-2 with a 6.11 ERA in 42 games last season but missed the entire second half with shoulder inflammation.
Coming off a very strong outing Wednesday, Eric Milton will make his third spring start 7:05 p.m. ET Monday night against the Pirates. Ian Snell is scheduled to start for Pittsburgh.