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7/25/2013 8:13 P.M. ET

McKenry, Liriano working well as battery mates

WASHINGTON -- Clint Hurdle has been looking for a comfortable way to fight the urge to keep Russell Martin permanently behind the plate. Catchers need regular breaks and, as his former coaches with the Yankees advised Hurdle, Martin isn't one to ask out.

"They told us, 'You put him in, he'll keep playing.' So we've got to find times to give him a rest," Hurdle said.

The Pirates may have found those times: When Francisco Liriano pitches. Michael McKenry caught Liriano for the second time in Wednesday night's 4-2 win over the Nationals, and the two again dialed up a nice synergy.

"They were right in sync," Hurdle said. "No shaking [off of signs by the pitcher], a good job of blocking [pitches in the dirt]. We've talked about different combinations that make the most sense to keep Michael involved, and that's a great thought."

In his two starts throwing to McKenry, Liriano has allowed one run and eight hits in 13 innings. Having the left-hander's vigilance about baserunners has also helped McKenry gain better control of the running game.

McKenry's rare start -- only his fourth this month -- became an overall success with his two-run single in the ninth, which at the time opened up a 4-0 lead but became the difference when the Nationals struck for two runs in the bottom of the ninth.

"My role has changed a bit," said McKenry, who last season spelled regular Rod Barajas more frequently, "but I just want to be the best I can be at whatever that role is."

Switch-hitting Walker sits against lefty

WASHINGTON -- The double-play tandem of shortstop Clint Barmes and second baseman Jordy Mercer didn't stay away long. Two days after Neil Walker's return, the Pirates revived that combination for Thursday's game against Washington southpaw Gio Gonzalez.

It may become a regular maneuver, given the switch-hitting Walker's ongoing troubles batting from the right side. A solid .254 hitter -- with all of his 21 extra-base hits -- left-handed, Walker is 11-for-57 (.193) as a righty.

"Neil is working to get better, and he is aware of the splits," manager Clint Hurdle said. "We have talked about [Mercer getting playing time at second against left-handers]. It's an option."

Thursday's move was also influenced by Walker's quick return from a mild right oblique injury. He had started the last two games, going 1-for-8 with two RBIs and having active games in the field.

"The back-to-back days and then the quick turnaround [for Thursday's 12:35 p.m. ET start] were part of it," Hurdle said, "so we weren't pushing over aggressively."

Since the start of the 2012 season, Walker has hit .277 left-handed and .228 right-handed. Only four of his 44 career homers have come from the right side.

Has there been any talk about having Walker forego switch-hitting?

"None whatsoever," Hurdle said. "He continues to work very hard on balancing it out."

In-game reps would help. The Bucs were facing a lefty starter for only the 20th time this season on Thursday -- the fewest among National League teams.

First number, last word

40: Major League parks in which A.J. Burnett has made a start, with his Nationals Park debut on Thursday. He is one of nine active pitchers to have appeared in as many ballparks (Jamey Wright, Darren Oliver, LaTroy Hawkins, Ryan Dempster, Kyle Farnsworth, Bruce Chen, Bartolo Colon, Andy Pettitte are the others).

"We talk about being extraordinary at the ordinary. We put away outs. That's our bling. A lot of guys in this league have bling on defense. Our bling is just playing hard." -- Hurdle, on the Pirates' unspectacular but steady defense, which had a lapse in the first inning on Thursday, with three errors leading to four runs en route to a 9-7 loss to the Nats

Worth noting

• Jose Tabata wore an air splint -- and the imprint of baseball stitches from a 95-mph fastball -- on the right forearm that stopped a Fernando Abad pitch in the ninth inning on Wednesday. Josh Harrison got the start in right field, but Hurdle felt Tabata, who had more difficulty throwing, could swing the bat off the bench.

Tabata pinch-hit in the ninth inning of Thursday's 9-7 loss to the Nats and struck out swinging. But Harrison was the Bucs' star hitter, going 3-for-5 with a two-run homer and a game-tying two-run single in the ninth. His home run was the fifth of his career and his second off Gonzalez.

• Closer Jason Grilli (forearm discomfort) continues to be medically evaluated in Pittsburgh. According to Hurdle: "We hope to have all the information by the end of the week to make an informative read of where we go next."

• Lefty Wandy Rodriguez had his "best of three throwing days" when he made about 60 flat-ground tosses from a distance of 80 feet on Wednesday, Hurdle said.

No timetable yet for Rodriguez's return to mound work, but Hurdle said, "He's heading in that direction. It was the best he felt mentally and physically. He was very encouraged."

Rodriguez went on the DL with forearm tightness on June 11, and the plug was pulled on his rehab assignment when he still felt discomfort in a late-June start. Subsequent to that, he was given an injection of platelet rich plasma.

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.