Ryan Braun grinned. He had just agreed to the largest contract in Milwaukee Brewers history.

"I really believe in the direction this franchise is headed," the NL Rookie of the Year said Thursday after his $45 million, eight-year deal was announced. "I'm extremely excited in our future."

Braun's contract, which runs through 2015, replaces the $455,000, one-year renewal the Brewers gave him in spring training. It includes a $2.3 million bonus this season and could increase to $51 million through escalators.

Braun hit .324 with 34 homers and 97 RBIs last season in 113 games after his May 25 debut. He hit his 10th homer in a 7-2 loss to the Dodgers on Thursday and has 30 RBIs and a .286 average this season.

Owners get tougher on drugs; maple bats next? Team owners unanimously ratified tougher drug testing rules and commissioner Bud Selig said he will now turn his attention to whether maple bats have become dangerous.

Players have until May 23 to ratify the drug agreement, which will increase the frequency of tests and the authority of the program's independent administrator.

Selig said the executive council discussed players' use of bats made from maple wood, which seem to be shattering more frequently — and in a more dangerous fashion — than those made of ash.

Asked if baseball would consider regulating the thickness of maple bat handles or even ban them entirely, Selig said it was too early to say.

"I don't want to get into any of that, because I'm not sure," Selig said. "We're working on a lot of things. But it's been a source of concern for me."

Pittsburgh Pirates hitting coach Don Long was injured when he was hit by the shattered fragments of a bat used by Pittsburgh's Nate McLouth during an April 15 game in Los Angeles.

Selig believes it's a trend.

"I watch a lot of games, and I'm concerned," he said.

Prior has shoulder re-examined: San Diego Padres pitcher Mark Prior was in Birmingham, Ala., to have his surgically repaired right shoulder examined by Dr. James Andrews.

The Padres will wait a few days before making any determinations on the former Chicago Cubs ace, but it's doubtful that Prior will be able to return to the majors by San Diego's target date of June 1.

When Prior felt discomfort in his shoulder at extended spring training in Arizona last week, he was sent back to San Diego for an MRI exam.

Riske heads to DL with hyperextended elbow: The Brewers put reliever David Riske on the 15-day disabled list because of a hyperextended right elbow and purchased the contract of journeyman minor league pitcher Mark DiFelice.

Riske hurt himself in the eighth inning of Wednesday night's 6-4 loss to the Dodgers and immediately left the game.

Riske, who signed a three-year, $13 million contract in the offseason, is 0-1 with one save and a 4.71 ERA in 18 appearances.

Valdez goes on DL with elbow injury: Merkin Valdez is almost two years out from reconstructive right elbow surgery, so the San Francisco Giants aren't about to take a risk with his health now.

The Giants placed the hard-throwing righty reliever on the disabled list with a strained elbow on his throwing arm, which isn't believed to be related to his surgery on Sept. 27, 2006.

He was slated for an MRI exam.

Valdez wasn't available for several days late last week because of tightness in his arm, said he was much better, then felt some discomfort again after he made his latest relief appearance Monday night against the Houston Astros.