There are three words that no pitcher or general manager ever wants to hear: Torn rotator cuff.

"It's frightening to hear those words," Houston general manager Tim Purpura said. "The first thing you ask is to what extent? Sometimes it can be tendinitis in the rotator cuff, sometimes it can be bursitis. It can be a lot of things before a rotator cuff tear. But when I hear rotator cuff tear, obviously you get really worried and you're concerned about a guy's future. It's definitely a very severe injury now as much as it was in the past."

Kansas City GM Dayton Moore is also among those who dread hearing a pitcher has a torn rotator cuff.

"The statistics show pitchers often don't return to their customary level," Moore said. "The success ratio of Tommy John [elbow ligament replacement surgery] is certainly much better, but with today's technology and the great work that so many physical therapists do and the intensity level that athletes have, they can get back."

They can get back, but in many cases they are never the same pitcher.

No hard statistics are available to document the disparity, but it is widely accepted that the success rate for pitchers returning from rotator cuff surgery is lower than the return rate for Tommy John surgery. Both happen all the time in the sport. And yet the latter has become fairly routine over the years to the point where pitchers undergoing Tommy John surgery often return to their previous level of performance within a year or so.

Such isn't the case with rotator cuff tears. It isn't that medical science has stalled on the subject, it is simply a case of more complex mechanics with the shoulder.

"Rotator cuff surgery is trying to repair a frayed tendon, comparable to sewing a small hole together or sewing a large hole together with shades of gray in between," said Dr. David Lintner, an orthopedic sports medicine specialist as well as head team physician for the Houston Astros. "The main task with Tommy John surgery [is] you are reconnecting a cable or tendon. With the rotator cuff, you're talking about the shoulder and repairing a muscle and a tendon. But it's more than just repairing it, you have to be able to repair the muscle and yet have it be extremely flexible."

That flexibility is at the heart of the difficulty in returning from rotator cuff tears and why teams keep their fingers crossed when waiting for pitchers with rotator cuff injuries to return.

This year, the list of pitchers dealing with rotator cuff ailments is lengthy, and includes Pedro Martinez of the New York Mets (currently rehabbing from surgery to repair a torn rotator cuff), Mark Mulder of St. Louis (rehabbing from surgery to repair a partially torn rotator cuff), Boston's Matt Clement (surgery on the labrum and rotator cuff), Baltimore's Kris Benson (out for the season following rotator cuff surgery), Minnesota's Jesse Crain (out for the season after surgery to repair labrum and rotator cuff tears), Cleveland's Cliff Politte (recently started rehab assignment in the Minor Leagues after undergoing rotator cuff surgery last August) and Washington's Joey Eischen (torn rotator cuff).

Extended rest and strengthening, rather than surgery, is an option for certain rotator cuff injuries.

Some have taken the non-surgical route for rotator cuff tears, like Bartolo Colon, who returned to the Angels in April after a stint on the disabled list, and Kerry Wood of the Cubs, who underwent labrum surgery in Aug. 2005 but chose offseason rehab for his partially torn rotator cuff rather than surgery.

Extended rest often is the preferred treatment for less severe rotator cuff issues. This season, that includes Philadelphia closer Tom Gordon (on the disabled list with rotator cuff inflammation), Washington's Ryan Wagner (tendinitis), Florida's Henry Owens (tendinitis) and Philadelphia's Freddy Garcia (inflammation).

Whether they choose surgery or strengthening, all pitchers with rotator cuff issues seek the same goal: To get their arm back the way it was before the problem. Whatever course they take, there's no guarantee the pitchers will get their wish.

Again, it comes back to flexibility. What works for the average person doesn't necessarily work for the power pitcher.

"When you fix a rotator cuff, the healing process tends to lead to more stiffness," Lintner said. "Say [the shoulder muscle] has 10 to 15 percent more [stiffness] after surgery. For a typical person, 10 to 15 degrees is not a problem, but for a pitcher it's night and day."

That can be the difference in a pitcher resuming his Major League career or not.

There have been a number of pitchers who came back from a torn rotator cuff, like Jimmy Key, Orlando Hernandez, Tony Armas Jr. and Joey Hamilton.

There have also been scores more who didn't, like Don Drysdale, Mark Fidrych, Wayne Simpson, Steve Busby, Mike Scott, Don Gullett, Matt Keough, Ben McDonald and John Rocker, to name a few.

A pitcher losing a percentage of his throwing flexibility consequently loses some of his previous velocity. A few miles an hour on a fastball can be career changing. There's also the possibility that the flexibility issues could impact the pitcher's control of his pitches. This potential double-whammy makes it obvious why the injury is met with such dread.

"With a complete tear of a rotator cuff, the odds are 50-50, I would say, of getting them back on the mound," Lintner said. "Typically [the patient] takes about four months off, then they start start to throw in six or seven months."

The success rate is not one that instills a lot of confidence, and that's why teams are wary when it comes to taking a chance on a pitcher who is attempting to return from a torn rotator cuff.

"You have to consider the severity," Purpura said. "Players who have already been playing and are back playing, certainly, we'd take a look at that. That's one of the big markers for us. What have they done since the surgery? If they've shown they've recovered and are able to play, that's something we'd look at.

"With amateurs, it's more problematic, because when you recover from rotator cuff surgery, you're usually not back to where you were before [the surgery], you're going to have some loss of velocity, control or whatever. In an amateur, it's a serious thing."

The success rate on coming back from a torn rotator cuff also depends on the severity of the tear.

That could be good news for St. Louis, for example, as Mulder's rotator cuff tear was intially thought to need only a debridement, or cleaning. A small tear was repaired, but at least it wasn't a complete tear.

Rotator cuff injuries will continue to scare pitchers and GMs, but there is hope for the future. Lintner, for one, has seen progress in the 15 years he's been doing the procedure.

"It's definitely getting better," he said. "Today they're done arthroscopically, just a few poked holes and then rehab. You used to have to splice through the deltoid muscle."