PITTSBURGH -- There's unlikely to be any budging by manager Clint Hurdle when it comes to how often he uses his relievers. He made that much clear on Friday.

Hurdle said he has a hard policy of not allowing a reliever to appear in more than three consecutive games. He developed the firm stance on the issue after numerous studies he did as a hitting coach. Hurdle looked into how pitchers fare in years after they pitched more than three days in a row and found consistent increases in injuries and ineffectiveness.

That was enough proof for Hurdle to set a hard line.

"It just doesn't make any sense," Hurdle said. "[There is] too much to lose. The risk versus the reward isn't good enough for me. You want to be tied to their arms as much as you can, not just to the results."

Hurdle said he has broken the rule a few times, though such circumstances are rare. He has done it late in the season with a team making a playoff push, and he's considered it with a closer who had a low pitch count in three straight appearances.

If the Pirates were to find themselves in such a scenario with closer Joel Hanrahan, Hurdle would call on Evan Meek or, if Meek wasn't available, Jose Veras in a save situation.

Ohlendorf exits with sore right shoulder

PITTSBURGH -- The severity of Ross Ohlendorf's shoulder injury, which prompted his early exit from Friday's 4-3 marathon win over the Rockies, is something the Pirates are expected to get a better grasp on over the weekend. In the meantime, the club can only hope that the ailment does not turn out to be similar to the one that cost Ohlendorf the final six weeks of the 2010 season.

The right shoulder discomfort surfaced in the third. Ohlendorf said he felt some tightness on one pitch, threw a couple more and then decided it was best for him to end his night there. After inducing a deep fly ball out, Ohlendorf summoned head athletic trainer Brad Henderson and then headed into the dugout with two out in the inning.

"I felt like I needed to come out," said Ohlendorf.

Ohlendorf said the area of discomfort is "very close" to the area that gave him problems last summer. He added, though, that he didn't think it was as bad this time.

"I'm pretty sure it's not," Ohlendorf said. "I'm not sure how it will feel tomorrow."

The Pirates could be forced to place Ohlendorf on the disabled list regardless, given how taxed the bullpen is after Friday's 14-inning game. With Evan Meek's health questionable as well, manager Clint Hurdle hinted strongly that the club will be calling up another pitcher before Saturday's game. That could leave Pittsburgh no choice, but to move Ohlendorf to the DL.

Should Ohlendorf be out for any extended period of time, Jeff Karstens, who pitched 3 1/3 innings of scoreless relief on Friday, would be the likely candidate to step into the rotation.

Tightness keeps Meek out of marathon win

PITTSBURGH -- It was not a particularly good night for Evan Meek to be deemed unavailable to pitch, but that's what it came to on Friday, after Meek felt tightness in his shoulder while playing catch that afternoon.

Both Meek and manager Clint Hurdle said the right-hander could be ready to pitch again as early as Saturday, and neither seemed particularly concerned that this would be a lingering issue. There was no talk about a possible disabled list stint, either.

Hurdle ruled Meek out before Friday's 14-inning, 4-3 win over the Rockies ever started, and he stuck with that decision, even after Meek volunteered to begin playing catch after the Pirates used their final available reliever, Garrett Olson.

"I was down there a little bit frustrated, but I appreciate the day to heal," said Meek, who last pitched on Wednesday. "They're smarter than I am. I wanted to pitch, but the smart thing was to give it a day. The last thing we want is to go out there and pitch and then have something not right turn from a day or two into a week or two. Just patience."

Added Hurdle, "The medical staff and I bit through our bottom lip about seven times as the game went on, but that's the decision we made before the game."

Lefty starter leads to Diaz's start

PITTSBURGH -- Matt Diaz has been waiting to see a left-handed starter since Spring Training ended. And on Friday, someone finally obliged.

After seven games against right-handed starters, the Pirates saw Colorado's Jorge De La Rosa take the mound in the second game of a four-game set, which meant that manager Clint Hurdle could insert Diaz into the lineup the way he intended to when the Pirates signed the outfielder to a two-year deal this winter. The plan all along was for Diaz to play against lefties, and for Garrett Jones to start against right-handers.

Hurdle placed Diaz fifth in the lineup on Friday and bumped Pedro Alvarez down one spot to hit sixth. The decision to change Alvarez's position in the batting order was dictated by Hurdle's desire to split up his left-handed hitters. Constructing the lineup this way allows for Diaz to hit in between the left-handed-hitting Lyle Overbay and Alvarez.

"Hopefully, you get a little bit more of an advantage," Hurdle said.

Alvarez is expected to slide back into the No. 5 hole when the Pirates face right-handers. The Rockies will send righties to the mound in both games this weekend.

Yates suffers another setback

PITTSBURGH -- Just as Tyler Yates was beginning to believe that his health issues were behind him, the right-hander finds himself sidelined with another right elbow injury.

Dr. James Andrews diagnosed Yates with a torn flexor tendon in his right elbow, which will sideline Yates for at least six weeks. Yates will be reexamined after that in order to determine the next course of action.

Yates sustained the injury pitching in a Minor League Spring Training game on April 2. The righty was expected to begin the year in Triple-A Indianapolis' bullpen after not making the big league club as a non-roster player this spring.

Though Yates has been recovering from right elbow surgery since undergoing the procedure in July 2009, this latest injury is not related. Yates' previous surgery was to repair the ulnar collateral ligament, which is different than the flexor tendon.

Bucs Bits

• The Rangers claimed right-hander Ramon Aguero off waivers from the Pirates on Friday. Aguero, who never played in Pittsburgh, was designated for assignment last week in order to open up a roster spot for reliever Jose Veras.

• Catcher Chris Snyder began his rehab assignment with High Class A Bradenton on Thursday, going 2-for-3 with a double. He also played behind the plate in the Marauders' 3-2 loss. Snyder had only limited at-bats this spring because of lower back soreness.

• Left-hander Joe Beimel made a rehab appearance with Bradenton on Friday, throwing one perfect inning. Beimel appeared in just two Spring Training games, due to a pair of left arm issues.