ST. LOUIS -- Outfielder/infielder Yamaico Navarro was all smiles on Tuesday after slamming his second career home run in the Pirates' 9-3 win over the Braves on Monday.

Navarro, the Pirates' jack of all trades, has seen limited duty this season but came through with flying colors in his fourth start of the season.

The native of Puerto Rico lined a two-run homer just over the left-field wall to help the Pirates to their biggest offensive showing of the season. The roundtripper gave Pittsburgh a three-run lead and allowed the club to pass the five-run mark for the first time this season.

Navarro, who played sparingly with Boston in 2010 and 2011 and spent part of last season with Kansas City, entered Monday's contest with just one hit in 13 at-bats. His 2-for-4 performance pushed his average to .176. He also added a run-scoring groundout in the seventh and tied a career high with three RBIs.

"I feel good at the plate, and I'm getting better every day," Navarro said. "My swing is ready."

Navarro hit his first Major League homer on July 2, 2011, in Boston's 10-4 win at Houston. He began this season with one homer and 14 RBIs in 42 games.

For now he is embracing his utility role, although he is hoping for more chances to play. He has started four times, at three positions (third base, second base, left field).

"I've just got to be ready when they need me," he said.

Hughes returns to the Pirates -- again

ST. LOUIS -- Jared Hughes is getting used to riding the Minors-to-Majors shuttle.

The 26-year-old right-hander began May in much the same way he spent April -- bouncing back and forth between Pittsburgh and the Pirates' Triple-A affiliate in Indianapolis.

Hughes, who is 0-0 with a 1.69 ERA in six Major League appearances this season, joined the Pirates on Tuesday afternoon for the third time in four weeks.

The up-and-down lifestyle doesn't seem to faze him.

"I flew out here and I'm ready to go," Hughes said. "I'm just glad to play the game. I'm happy to be here. I'm fresh. I'm going to be ready from the word go."

Hughes replaces Evan Meek, who was sent to Indianapolis following Monday's game in Atlanta.

A standout during his days at Long Beach State, Hughes made the Opening Day roster and made five appearances before being optioned to Indianapolis on April 21. Four days later he was brought back up for a 24-hour stretch when Pittsburgh had to play a doubleheader against Colorado. After pitching a scoreless inning against the Rockies, Hughes returned to Indianapolis. He threw a scoreless inning at Durham on Saturday in his most recent outing.

Manager Clint Hurdle is comfortable using Hughes in any role.

"We've used him for one-inning stints, for multiple innings," Hurdle said. "He's got a power sinker with a breaking ball and an occasional changeup. He's come out of the gate pretty clean."

Hughes relies heavily on that sinker, a pitch he is still working to perfect.

"My key is to keep the ball down at all times," Hughes said. "I need to fine-tune and keep learning as time goes on. I'm going for the very bottom of the zone."

Hughes has not allowed an earned run in four of his six outings. He surrendered one run in three innings against the Cardinals on April 20.

Selected by Pittsburgh in the fourth round of the 2006 First-Year Player Draft, Hughes went 0-1 with a 4.09 ERA in 12 appearances last season. He had a solid spring but was unable to find a regular role because "the stable was full," says Hurdle.

Home-plate umpire Bucknor leaves game early

ST. LOUIS -- The Cardinals and Pirates finished their series opener on Tuesday with an umpiring crew of three after CB Bucknor exited with an undisclosed injury in the seventh inning.

Bucknor, who was assigned to home plate, was in obvious discomfort, stepping away a few times in the seventh. At one point the Cardinals' trainer came out to visit with Bucknor, who was joined by the rest of the umpiring crew during the discussion.

A few minutes later, Bucknor asked second-base umpire Dan Iassogna to return to the dressing room, where Iassogna put on his plate gear.

When the Pirates made a pitching change during the bottom half of the inning, Iassogna took Bucknor's place behind the plate. Bucknor did not return.

Karstens plays catch in Florida on Monday

ST. LOUIS -- Right-hander Jeff Karstens, on the disabled list with inflammation in his right shoulder since April 18, played catch on Monday at the club's Minor League facility in Bradenton, Fla.

He is still more than a month away from returning to the rotation.

The 29-year-old left his third start of the season, against Arizona on April 17, after one inning because of stiffness in the shoulder. He gave up three hits and two earned runs.

"He's going to continue throwing for a while," manager Clint Hurdle said. "He'll start with catch, go into a little distances and eventually move to some flat ground work -- and then to the mound."

Karstens went 9-9 with a 3.38 ERA last season, the best among Pittsburgh starters. He established career highs in wins, starts (26), strikeouts (96) and innings pitched (162 1/3).

Worth noting

• Neil Walker carried a nine-game road hitting streak into Tuesday's game. He is 18-for-34 with six RBIs in that span.

• Pittsburgh will play nine of its next 12 games against National League Central foes, beginning with the three-game set in St. Louis.

• Manager Clint Hurdle, always quotable, is old school and not into social media.

"I'm a twit -- I don't tweet," Hurdle said.

• Right-hander James McDonald posted career highs in strikeouts (10) and pitches (114) in Monday's win at Atlanta. He allowed seven hits and three runs over 7 2/3 innings.