PITTSBURGH -- Without a doubt, the Pirates will be one of the most fascinating teams to watch in the weeks leading up to the July 31 non-waiver Trade Deadline.

The elements for intrigue are many: one of the Majors' best records, pitching surplus both in the rotation and the bullpen, no glaring holes.

Now add the experience of last season, when the Bucs likewise approached the Trade Deadline on a high, made several moves then, coincidentally or not, crumbled. General manager Neal Huntington has since conceded that some criticism of him tinkering with the club's chemistry might have been warranted.

So how do you approach it now?

"You always need to look and see if you can add to the team strength," said manager Clint Hurdle, who soon will participate in front-office conclaves to determine the club's approach. "We have a good team. I like how the guys have bound and figured out things together. Everyone has everyone else's back. We've been without ego. You pay attention to chemistry, and try to do the right thing."

Rodriguez, McDonald deal with injury setbacks

ATL@PIT: McDonald mows down nine Braves in six frames

PITTSBURGH -- The uglier underside of the dark-horse pitching depth that has carried the Pirates to the top of the Major League standings -- the injuries that have put that depth into play -- got a bit drearier on two fronts Saturday.

Wandy Rodriguez and James McDonald are both dealing with setbacks that are certain to shelve them for a long time. A.J. Burnett, another sidelined member of the season-opening rotation, is making good progress from the torn left-calf muscle that landed him on the DL two weeks ago.

Rodriguez, who experienced tightness in his left forearm while doing some flat-ground throwing on Friday, has been shut down and has an appointment with the team's medical staff. It is the same condition that forced him out of a June 5 start in Atlanta and onto the DL.

McDonald will see Dr. Keith Meister in Dallas on Tuesday for confirmation of diagnosis of the source of his shoulder discomfort by team doctors. McDonald declined to disclose that diagnosis, characterizing it as premature.

If Dr. Meister's findings differ, McDonald plans to seek a third opinion from Dr. James Andrews. Otherwise, he will turn his attention to curing the condition that has ailed him all year.

"I'm eager to find out just what's going on," said McDonald, who conceded that he hasn't felt right, even while he was part of the Pirates' regular rotation through April. "At the beginning, there really was no pain, it just felt different. Then when it started to hurt, I thought, 'There's something wrong. We've got to look at this.'"

McDonald was on a conservative throwing program until starting a Minor League rehab assignment on May 27.

"After not throwing for a while, my first couple times out, I felt fine," McDonald said. "Then the same pattern started over again, where I couldn't get loose and had the discomfort."

McDonald made the last of his six rehab starts on June 22.

On the positive side, Burnett had a problem-free 38-pitch bullpen session on Friday. On Tuesday, he will throw a simulated game spiced with elements of his biggest challenge, the ability to charge off the mound to field the position.

Worth noting

• The Pirates came to terms with three more selections in the 2013 First-Year Player Draft: outfielder Nick Buckner (14th round), right-hander Billy Roth (16th) and left-hander Will Kendall (30th). Buckner and Roth have been assigned to the Gulf Coast League Pirates, Kendall to West Virginia.

The club has now signed 22 of its 41 selections.

• Jared Hughes (shoulder inflammation) is scheduled to throw his second bullpen in five days on Tuesday; Hughes threw 25 pain-free pitches, mostly fastballs, in Friday's session.

• Jose Tabata (strained left oblique) could be days from rejoining the Bucs. He went 2-for-3 with Indianapolis on Friday, is scheduled to play nine innings Sunday and be re-evaluated after a couple of additional rehab games with Indianapolis.

• Travis Snider, who came out of Friday night's game with a bruise after fouling a ball off his foot, was kept out of the lineup as a precaution, but he said he'd be able to come off the bench if needed.

First number, last word

49: Most wins through June in Pirates history, by the 1971 World Series champions. Today's Pirates went for win No. 50 on Saturday night.

"Do you know how many times I still hear, 'What's going to happen late?' I believe I know what's going to happen, but there are people who are never going to believe. I listen to some people and go, 'Wow, you really think we're going to blow up again? That's what you got?' I don't." -- Hurdle, on the skepticism, healthy and somewhat natural, being faced by his MLB-best Pirates.