Jonathan Papelbon’s success has been so constant that any poor outing leads to the creation of a government commission to determine the cause. Such seemed the case last week, when the Red Sox closer had an unusual stumble.

In a three-appearance span from September 9-14, Papelbon blew one save and nearly hacked up another, permitting two earned runs in a three-game span after doing so in just eight of his first 191 relief appearances. The natural instinct was to wonder whether the pitcher’s workload had caught up with him.

That such questions would be asked was somewhat surprising. The Red Sox have been among the most conservative teams in baseball in regulating the usage of their pitchers in recent seasons.

The team has been unafraid to rest their relievers in crucial games. That stance is part of an effort to ensure health and productivity over the full span of a seven-month season.

Relievers, after all, are extremely volatile from year to year in no small part because it is so difficult to regulate the physical stresses that they face. They must warm up, sometimes multiple times, for a game that they may never enter.

Whereas it is fairly easy to establish a routine for starters, relievers cannot follow a straightforward weekly script. For that reason, the Sox insist on having objective measures of the strength and arm stability of their bullpen members.

While manager Terry Francona and pitching coach John Farrell are ultimately responsible for deciding whether to use a reliever, their choices are always made with the training and medical staff. That ensures that in-game decisions are made with long-term health in mind, leading in many cases to greater workload restrictions for Sox relievers than those on other teams.

Towards that end, pitching coach John Farrell noted this spring that the Sox try to avoid using pitchers for three straight days.

“I think there (were) only a handful of times (in 2007) when pitchers pitched on three consecutive days. (Francona) and I both believe strongly in avoiding the third day and riding the hot hand, for lack of a better term,” said Farrell. “We make every effort to stay away from that as much as possible.”

In that context, Papelbon’s workload was something of a surprise. For a one-week span, the pitcher was used as extensively as at any time (not counting last year’s playoffs) since 2006. That period coincided with a sudden vulnerability for a pitcher who is typically a force of nature.

Papelbon threw on three straight days on September 7-9, the third time this year that he had entered back-to-back-to-back games after doing so just once in 2007. One could argue that he did the same on September 12-14, having warmed up (without entering the game) on the first day, and then entering contests in each of the next two. In both cases, Papelbon allowed two runs in the last of the three straight games in which he pitched.

While Papelbon downplayed the issue, however, there is little question that pitching with such regularity can affect a reliever. Several Sox pitchers noted that the physical effects of pitching on three straight days are palpable.

“Absolutely,” Sox reliever David Aardsma said of whether pitching in three straight games was fatiguing. “You’re not as sharp, and you’re generally not throwing as hard. If you are throwing as hard, the ball’s not jumping out of your hand and exploding like it would that first or second day.

“You can’t do anything (about it). It’s one of those things. It’s like you’re doing a really strong leg workout for three consecutive days. That third day, you’re going to be tired, exhausted.”

Different pitchers, however, react differently. Mike Timlin, for instance, suggested that he has often enjoyed pitching regularly, feeling that he gains better touch on the ball and that his mechanics can get locked in by frequent usage.

That said, the veteran has seen pitchers who struggle with such workloads.

“Some guys lose velocity, some guys lost command, some lose both (when pitching while fatigued),” said Timlin. “It’s an individual thing. It depends on who you are and how you pitch.”

Manny Delcarmen feels that his location is most affected by the frequent usage.

“It definitely takes a toll on you. I’d rather throw back to back days and not throw on that third day,” said Delcarmen. “Everyone tries to tell you that when you feel a little bit fatigued, just try to stay behind the ball, don’t try to overthrow. If you have to throw 90 miles per hour, they’d rather have us hit our spot than not hit that spot, try to overthrow and be all over the place. “

Of course, the Sox would prefer that their pitchers not have to make choices between velocity, movement and command. The result is a more cautious approach to pitcher usage than is found on other teams.

“They definitely give guys more rest here (than elsewhere),” noted Aardsma, who has also pitched for the Giants, Cubs and White Sox. “They rest guys until the points when it really matters, obviously, at the end of the season.”

Now that they are at that point, the shackles may get loosened. Whether and how that affects Papelbon and the rest of the relievers could go a long way in determining the complexion of the team in October.

Alex Speier is a Senior Writer for WEEI.com.