"We're trying to win," manager Manny Acta said. "It's not fair to us. It's not fair to the whole organization. It's not fair to the fans. We're trying to fix our bullpen somehow, some way. I'm glad we're doing everything we can."

Hinckley, 26, entered 2009 in good standing within the organization but quickly fell out of favor with his performance on the mound. He allowed 20 men to reach base in only 9 2/3 innings, including 11 walks.

The final straw came Wednesday night in a 10-3 loss to the Los Angeles Dodgers in which Hinckley entered with the bases loaded and proceeded to give up two runs, one on an RBI single and one on a 3-2 fastball that hit the backstop on the fly.

The Nationals now have 10 days to either trade Hinckley, once considered the organization's top pitching prospect, or pass him through waivers. If he goes unclaimed, he can either report to Syracuse or elect free agency.

Villone, 39, gives Washington another veteran arm with something of a proven track record. In 14 big league seasons with 11 different teams, the left-hander owns a 56-59 record and 4.75 ERA. Signed by the Nationals to a minor league deal on April 11, he had a 2.35 ERA in eight appearances with Syracuse.

He is the fourth veteran reliever added to Washington's roster in the past two months.

"We do already have young guys starting for us," Acta said of his starting rotation, which has an average age of 24. "We need to protect those guys at the end of the ballgame, and it hasn't been happening."

Streak reaches 25

Ryan Zimmerman has no sense of the dramatic - at least not during his career-best hitting streak, which reached 25 games Thursday night.

For the fourth time in five days, Zimmerman hit safely in his first at-bat, this time lacing a line drive up the middle for a single against Dodgers starter Randy Wolf.

During this stretch, the Washington third baseman has come through with a hit in his first plate appearance 10 times. He has done it in his second plate appearance nine times.

The streak, already the longest in Nationals history, has matched the majors' longest hit streak in two years. Texas second baseman Ian Kinsler hit in 25 straight games last season.

Next on the list: Moises Alou, who had a 30-game streak in 2007 for the New York Mets.

NEW SERIES

WASHINGTON Nationals at ARIZONA Diamondbacks

Where: Chase Field, Phoenix

Friday: 9:40 p.m., RHP Shairon Martis (3-0, 4.60) vs. RHP Yusmeiro Petit (0-2, 7.84), MASN2

Saturday: 8:10 p.m., LHP John Lannan (1-3, 4.59) vs. LHP Doug Davis (2-4, 3.52), MASN2

Sunday: 4:10 p.m., LHP Scott Olsen (1-3, 6.54) vs. RHP Max Scherzer (0-3, 3.38), MASN2

Series breakdown: The Diamondbacks entered the season with high hopes of contending with the Dodgers in the NL West but have faltered - reportedly costing manager Bob Melvin his job Thursday - because of an ineffective lineup and a major injury on the pitching staff. Ace Brandon Webb, a former Cy Young Award winner, has pitched only four innings this season and is out for at least another month with a shoulder injury. It hasn't helped that Arizona is hitting an NL-worst .225 with an abhorrent .297 on-base percentage. Former Nationals player Felipe Lopez (.311, three homers, six RBI) has been one of the few bright spots.