SAN DIEGO -- Brewers first baseman Mat Gamel needs surgery for a torn ligament in his right knee and will miss a significant amount of the remaining regular season, general manager Doug Melvin confirmed on Wednesday.

Gamel was hurt chasing a foul popup in Tuesday's loss to the Padres at Petco Park and underwent an MRI scan after the game. His right leg was completely immobilized and Gamel moved about the clubhouse on crutches Wednesday afternoon before traveling to Milwaukee to meet with the Brewers' head physician. Dr. William Raasch will set a timetable for surgery.

Melvin and other Brewers officials stopped short of declaring Gamel lost for the season, with Melvin saying only that, "we're anticipating long term." Right-hander Yovani Gallardo tore his ACL on the same date in 2008 and wound up returning to the mound in the final week of the regular season, then started Game 1 of that year's National League Division Series against the Phillies.

"[Gamel] waited for his chance and his opportunity, and now ..." Melvin said, leaving that thought unfinished. "That's what's tough about it. This year was a big year for him."

Gamel spoke only briefly to reporters before departing for his flight. Immediately after taking his tumble Tuesday, he thought he was OK. Gamel finished the first inning and briefly stepped on deck in the top of the second, only to return to the dugout after one tentative swing.

"I knew that I couldn't go," he said. "It stinks."

Gamel has dealt with bad breaks before. He was injured in three consecutive Spring Trainings before reporting to camp in 2012 in terrific shape, committed to taking over first base for Milwaukee. Melvin made clear that Monday's injury fell into the category of accidental and not preventative. 

"I play the game hard, man," Gamel said.  "Unfortunately, when you play the game hard, sometimes you've got to pay." 

Gamel's teammates expressed disappointment upon learning of his tough break.

"I was praying for him as soon as it happened, praying for him last night, praying for him this morning for it to be as good of news as possible, and obviously it wasn't," said Travis Ishikawa, who becomes the Brewers' primary first baseman with Gamel out. "I'll continue to pray for him that his recovery is 100 percent and speedy."

Said right fielder Corey Hart: "You feel for him. It's a big year. He finally got a chance, and it was cut short."

Ishikawa, Hart among answers at first base

SAN DIEGO -- Right fielder Corey Hart spent a significant amount of time during batting practice Wednesday taking grounders at first base, the most public sign of the Brewers moving on in the wake of Mat Gamel's significant knee injury.

As disappointing as the injury was for Gamel, it was equally challenging for the team, which was very encouraged by Gamel's first month following in Prince Fielder's footsteps. Now the Brewers must settle first base for the foreseeable future, while Gamel faces surgery for a torn ACL.

Travis Ishikawa will be the regular first baseman in the near term and utility man Brooks Conrad, who started at first base for Triple-A Nashville on Wednesday, will be recalled in time for the Brewers' series opener Friday at San Francisco.

Options down the road include Hart, who said he would spend the next few days during batting practice reacquainting himself with his original position. The Brewers are deep in outfielders, so Hart could, in time, move to first base if Ishikawa does not work out. 

"I might sneak in there a little bit, get a couple of starts here and there to see how it goes," said Hart, who wondered aloud of the first opportunity to start could come Saturday against Giants left-hander Madison Bumgarner. "I think it really depends on how comfortable I can be over there. ... If [Ishikawa] starts raking, then it might not be an issue. We all think he's obviously capable."

General manager Doug Melvin also instructed his staff to compile a list of players available in free agency or potentially available in trades. Asked about veteran free agent Derrek Lee, Melvin said vaguely, "He's one name out there." 

In the longer term, the Brewers will face the same uncertainty in 2013 they carried into this season: Can Gamel be the guy at first base?

"At the end of the year, we're still [not] going to know who's our first baseman," Melvin said. 

Ishikawa is a premier defensive player. He will be on familiar ground this weekend in San Francisco, where Ishikawa played his first 281 Major League games from 2006-10.

"I was hoping to get a start up there, but not like this," Ishikawa said.

Big matchups await in San Francisco

SAN DIEGO -- Matchups against the Giants' top three starting pitchers only partially prompted the Brewers to keep their own big arms on regular rest this weekend, manager Ron Roenicke said.

Roenicke has opted to use Thursday's off-day to skip Marco Estrada's turn in the rotation, meaning Zack Greinke, Randy Wolf and Shaun Marcum will be pitching on regular rest at AT&T Park. Greinke will face Tim Lincecum, Wolf gets Madison Bumgarner and Marcum will face Matt Cain.

"I think when you gather information, you gather five different things and [head-to-head matchups] is one of them," Roenicke said. "It's looking at the whole picture, and looking at the individuals and what's going on."

Estrada will be available in the bullpen over the weekend. He'll slide back into the rotation on Tuesday.

The Greinke-Lincecum matchup on Friday night marks a compelling start to the weekend series.

"I become a fan in those instances," Brewers right fielder Corey Hart said. "Those pitchers' duels are fun. As a hitter, you want your stats, but those games are so intense, because you know every play could be the play. So Friday could be fun."

Last call

• Brooks Conrad, the last player cut from the Brewers' Spring Training camp, has been on fire for Triple-A Nashville. He homered for the third straight game Wednesday to extend his hitting streak to 10 games. The Brewers will have to clear a 40-man roster spot before promoting him for Friday's game.

• The Brewers are adding a wrinkle to their annual S.C.O.R.E. For Excellence program, challenging students at five Milwaukee schools to improve their grades over the course of a month. All of the participating students will get tickets to a game this season, and the most improved grade level at each school will get a T-shirt for each student, a visit from a Brewers player and $2,500 to improve academic achievement.

S.C.O.R.E. is an acronym for School, Community, Opportunities, Role Models and Excellence with an emphasis toward education, interaction and life skills. Brewers players and coaches will visit Milwaukee-area schools on May 21 to engage students in a dialogue about the importance of those elements.