John McDonald eventually will spend time on a minor league rehabilitation assignment, manager Clint Hurdle said Saturday.
McDonald is battling an elbow injury as well as a lower-back strain.
McDonald went on the 15-day disabled list Wednesday because of the back strain, but Hurdle said Saturday that McDonald's elbow had been bothering him. McDonald had ice wrapped around his right elbow Tuesday after the game.
"You want to make sure the guy can play and throw," Hurdle said. "At the point in time where it's pertinent, I anticipate us getting him back out."
McDonald entered the game Tuesday in the 11th inning, replacing Clint Barmes at shortstop as part of a double switch. He led off the bottom of the 11th, but Ryan Braun robbed him of an extra-base hit with a diving catch. McDonald was replaced before the 12th began.
Hurdle said the elbow pain developed gradually, not as a result of any impact.
"I think for whatever reason, both kind of jumped on him at the same time," Hurdle said.
"He works extremely hard. As much as he was working on his fielding and his pregame routine, he's taking a million swings, too. It could have been just the perfect storm that everything caught up with him. Sometimes, one injury could trigger another one."
McDonald can come off the DL May 30 at the earliest.
James McDonald improves
James McDonald, on the 15-day disabled list because of right shoulder pain, is on track to pitch a bullpen session Tuesday, Hurdle said.
McDonald can come off the DL at any time, but has only been playing long toss thus far.
"I think so far he feels good," Hurdle said.
"That's why we're talking about Tuesday. That's a day we'll shoot for and, hopefully, we can pull off."
D'Arnaud moves to Class AA
The Pirates moved infielder Chase d'Arnaud's rehab from Class A Bradenton to Class AA Altoona Saturday. D'Arnaud went 2 for 6 with a triple in two games for Bradenton.
Surgery to repair a torn ligament in d'Arnaud's left thumb forced him to start the season on the 60-day disabled list.
Walk-off errors hot topic
Hurdle said he saw a walk-off error while he was the Texas Rangers' hitting coach in 2010 that was more bizarre than the bases-loaded walk-off error Houston committed on a pop fly Friday night.
Hurdle was mum on specifics, saying only that "you can look that one up and see if you can dig it out." He might have been referring to Sept. 29, 2010.
The Rangers entered the bottom of the ninth tied, 5-5, with the Seattle Mariners. Mitch Moreland walked with two outs. Pinch-hitter Nelson Cruz struck out on a pitch in the dirt, but the ball bounced away from catcher Guillermo Quiroz. Quiroz's throw to first went into right field, Moreland scored from first, and the Rangers won, 6-5.
Hurdle said the Pirates can give the video of the win Friday night to their minor league coordinators so it can be used as a teaching tool.
"You can take that tape and you can take that down to West Virginia, you can take that to Bradenton," Hurdle said. "Those young managers are pulling their hair out, and the kids -- they're not playing the game and they're not fundamentally executing. Show them a big league game and say, 'Wow. It can happen.' "pirates
Bill Brink: firstname.lastname@example.org and on Twitter @BrinkPG.