OAKLAND -- After just three-plus innings of service, Vin Mazzaro's initial 2010 stint with the big league club is over. The right hander was optioned to Triple-A Sacramento after Tuesday's game, when he allowed four runs (all earned) on two hits and four walks while striking out four.
The A's have called up Henry Rodriguez, a 23-year-old righty, to take Mazzaro's place. Rodriguez, who features a mid-90s fastball, has tossed 9 1/3 scoreless innings to start the season.
"He's throwing the ball pretty well," A's manager Bob Geren said. "The reports on him from our Triple-A staff are that he's throwing strikes and obviously velocity has never been a question. It's just his command and his command has been pretty good."
Since the A's have off-days on Thursday and Monday, Geren said the team will go with a four-man rotation for the time being and hope Justin Duchscherer will be healthy by the time Oakland needs a fifth starter. Geren said Duchscherer was scheduled to receive a cortisone shot to his injured left hip at noon on Wednesday.
Rodriguez made three relief appearances for Oakland last season, allowing two runs (one earned) in four innings of action.
Throughout his Minor League career, Rodriguez has always been able to record strikeouts. In 2009, his strikeout-per-nine-innings rate was 15.2.
Rodriguez has also handed out plenty of free passes, though, as his best strikeout-to-walk ratio (2.1) came in 2009. This season, that figure has ballooned to 4.7 in eight appearances.
Bullpen showing early-season success
OAKLAND -- When Michael Wuertz made his season debut on Tuesday night, it signaled the bullpen's return to full strength. With the rash of injuries the A's have faced this season, the bullpen is now the only fully intact unit.
On Tuesday, it completed six innings of relief work, allowing two earned runs on four hits, to secure the 7-6 win.
"Excellent job by the bullpen last night," A's manager Bob Geren said. "When you have to take your starter out in a one-run game that early on, you have to have a really solid performance by everybody."
Finishing up the job once again was A's closer Andrew Bailey, who is stringing together an impressive sequence dating back to last season.
The reigning American League Rookie of the Year has converted his previous 25 save opportunities and currently boasts a career-high 19 2/3 innings scoreless streak.
Still, Bailey was quick to deflect praise to the middle relievers after Tuesday night's game, when he earned his fourth save of the year by recording the final four outs.
"I'm the first one to say that the closer's role may be overrated," Bailey said. "You don't win the games in the ninth inning, you win the games in the fifth, sixth seventh innings."
As proficient as Bailey's been, he hasn't had many opportunities to close out games this season. Oakland has had just five save opportunities this season, while Kansas City leads the league with 15. The A's remain the only Major League team that hasn't blown a save.
Kouzmanoff starting to heat up
OAKLAND -- After suffering through a mini slump during mid-April, it appears Kevin Kouzmanoff is starting to heat up.
Since his batting average bottomed out at .210 on April 21, Kouzmanoff has been among Oakland's best hitters. In an 11-game span, Kouzmanoff is hitting 16-for-43 (.372) and has raised his average to .273.
"He went through a period of making a few adjustments," A's manager Bob Geren said, "but now he feels good."
Geren said he also expects Kouzmanoff to get more comfortable in the coming weeks, as he starts to face teams for the second time. Oakland will host the Rays, whom it played in Tampa Bay last week, for a three-game set this weekend before facing all three of its American League West opponents in succession.
A's manager Bob Geren said Justin Duchscherer received a cortisone shot Wednesday afternoon and will attempt to throw May 10 or 11. Duchscherer is battling inflammation in his left hip and missed his scheduled start on Tuesday. ... Rajai Davis has a 12-game hitting streak against the Rangers and is hitting .354 (17-for-48) during that span. ... Kevin Kouzmanoff's bad throw in the sixth inning Wednesday was his fourth error of the year. He only had three in 139 games for San Diego last year. ... Ryan Sweeney had his 37-game streak of reaching base safely snapped on Wednesday.
Alex Espinoza is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.