"I'm ready to go. No discomfort whatsoever," said Walker, who had the six-stitch souvenir from being stepped on by Cardinals shortstop Pete Kozma removed last Tuesday.
Although both Mercer and veteran Brandon Inge did a solid job in Walker's absence, manager Clint Hurdle was happy to have the Pittsburgh Kid back.
"He stabilizes our lineup, strengthens it," Hurdle said. "When he's not around, you feel his absence."
Walker went 5-for-12 in four games with the Double-A Curve. Prior to his April 26 injury, Walker hit .253 in 23 games, with eight RBIs.
Mercer, normally a shortstop and a leading contender for the Pirates' 2014 job at that position, started eight of the team's last nine games at second base. He hit .258 during the stint, and on Saturday enjoyed his first career two-homer game in New York against the Mets.
"He added value for us, and for himself, while he was here. He played very well. I'm a fan; in 2014, he could very well be the guy who gets to play shortstop," said Hurdle, who cryptically suggested that might happen even earlier. "Coming out of Spring Training, we all felt his time was coming -- and it might very well be this season. When he's back, his role could be significantly different than what it was this time."
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.