ST. LOUIS — Social anxiety disorder is the term the St. Louis Cardinals used when they put shortstop Khalil Greene on the disabled list.

Cincinnati slugger Joey Votto is out because of stress-related issues linked to an inner ear infection that caused dizzy spells.

Not exactly typical baseball ailments. But Greene and Votto aren’t the only prominent players trying to overcome mental obstacles this season more so than pulled hamstrings, sprained ankles or sore arms.

Detroit lefty Dontrelle Willis missed the first six weeks with an anxiety disorder, similar to the problem that prompted Kansas City Royals ace Zack Greinke to give up the game three years ago.

Is the pressure and stress of big league baseball causing players to snap?

‘‘The game can become all-encompassing,’’ Reds manager Dusty Baker said. ‘‘Day and night.’’

Cardinals general manager John Mozeliak said Greene was being treated for symptoms of anxiety but would not specify what type of treatment, citing privacy laws.

Since going on the DL, Greene has been on the field every day for early workouts, playing catch and taking grounders.

Votto, however, wasn’t with the Reds this week for their series in St. Louis. The first baseman, runner-up for NL Rookie of the Year last season, is getting some time away from the game to sort out his troubles — despite a .357 batting average.

Reds spokesman Rob Butcher said at Votto’s request the team was not releasing any information beyond the fact he was on the DL for stress-related issues.

Baker thinks serious stress is the price some must pay for reaching an elevated stage so quickly, set for life in their 20s while their less athletic peers slowly climb the career ladder.

‘‘I’ve always said sports is probably one of the few professions where you reach your goal at a very young age,’’ Baker said. ‘‘And then what?’’

Then what? Success or failure on a daily basis with thousands cheering or jeering in the stands and untold masses watching from home. Seeing the big plays rerun a dozen times, wincing as the gaffes seem to get even more attention.

Baker said baseball thoughts have a way of interrupting a sound sleep, for managers as well as players. The result can be a loss of balance in life.

Salaries have long been a sore spot for some, and as the numbers go up so do the complaints.

‘‘People push money in your face all the time, especially when you’re losing,’’ Baker said. ‘‘There’s a lot more pressure, a lot more coverage, a lot more everything.’’

Cardinals manager Tony La Russa isn’t sure that’s the entire answer, pointing out that anxiety issues have been part of the game at least since he was hired as manager of the Chicago White Sox in 1979. Sure, there are more media outlets, more opinions, more telecasts, ever-incessant highlights, but he said pressure has always been there.

‘‘As long as I’ve been around, the level of distractions have been significant,’’ La Russa said. ‘‘You’ve got money and you’ve got media and even when it’s there a little, it’s still a lot.’’

La Russa does his best to ignore the chatter, and advises his players to do the same, telling them the game is difficult enough without letting the criticism — or the praise — get into their heads.

‘‘I don’t know who’s paying attention to bloggers, I really don’t,’’ he said. ‘‘That’s just part of the cost of doing business, man.

‘‘The point is, you take compliments the way you do criticism. You ignore them. You can’t live with either one, so you just do the best you can.’’

Votto missed 12 starts and left two other games early during a 17-game stretch last month due to dizziness caused by the ear infection. He went on the DL in late May while leading the NL with a .464 on-base percentage and ranking among the league leaders in several other categories. General manager Walt Jocketty has said the timeline for Votto’s return is unclear, and Baker was waiting patiently for Votto to telephone.

‘‘He’ll call,’’ the manager said. ‘‘He’s probably one of the most respectful players I’ve had — on and off the field. He’s a great example.’’

Greene’s poor 2008 season with the Padres ended prematurely when he punched a dugout wall and broke his left hand in July. The Cardinals acquired him counting on a rebound season more like 2007, when he had 27 homers and 97 RBIs, than ’08, when he slumped to a .213 average with only 10 homers and 35 RBIs.

Thus far, despite great initial optimism off a productive spring, this season has been much like the last, with Greene hitting .200.

The Cardinals were unaware of Greene’s past anxiety issues when they made the deal, but Mozeliak hesitates to criticize the Padres for offloading their problems. St. Louis hopes Greene can resume his career when he’s eligible to come off the DL in mid-June.

The Cardinals initially reduced Greene to a utilityman role when the anxiety issues resurfaced, giving him a few starts and some pinch-hit duties, but decided late last month that the better course might be a break.

‘‘We all thought it was in his best interest to try to get himself over the hump, get himself where he’s starting to see some incremental benefits to what he needs to work on,’’ Mozeliak said. ‘‘Taking the day to day baseball out of that equation just seemed to simplify things.’’