SAN FRANCISCO » Florida Marlins owner Jeffrey Loria stood at the center of the visiting clubhouse, holding a Marlins cap in his hand and flashing a smile behind his sunglasses.

He was clearly the happiest person at AT&T Park.

With the home fans still stunned and saddened over the possible season-ending injury to star catcher Buster Posey, Anibal Sanchez threw a five-hitter for another complete game in San Francisco to lead the Marlins to a 1-0 win Thursday and cap a three-game sweep.

"The sweep here against a good team is great," Florida manager Edwin Rodriguez said. "The down side is what happened the other night. Other than that, a good three wins."

The injury to Posey hovered over the game well before the start.

The play occurred Wednesday night when Florida’s Scott Cousins tagged up from third and bowled over the Giants’ catcher for the go-ahead run in the Marlins 7-6, 12-inning victory.

MRI exams on Posey on Thursday showed that he fractured a fibula in his lower left leg and had three torn ligaments on both sides of his left ankle, Giants trainer Dave Groeschner said.

In a news conference after the Giants’ 1-0 loss, Groeschner said Posey had three MRIs — on his ankle, his lower leg and his left knee. The knee tested OK, and the club was aware of the fracture following X-rays taken after Wednesday night’s game.

Groeschner said the ligament tears in the ankle are by far the most disconcerting.

"The fracture’s going to heal," he said. "We’re still getting some other opinions, so we don’t have all the information we want yet. We’re just trying to decide 100 percent what to do with the ankle."

The trainer said Posey has a medial ankle sprain, a lateral sprain and a syndesmosis sprain, which is the ligament on the front of the foot leading up to the tibia. Groeschner said he has tears on both sides of his ankle. But even though there is still significant swelling, he said the Giants want Posey to have the surgery as soon as possible.

"We’re not going to waste too much time," he said. "We want to get this done within a week or so. But we want to gather all the information, and whether it’s this weekend or early next week, we’ll have to wait and see."

Groeschner said the Giants have had similar injuries within their system and players have made full recoveries. He said Posey’s injury is more common in football, and the club was contacting doctors with experience in such ankle traumas to better determine a course of action.

Asked if he thought Posey would make a full recovery, the trainer was optimistic.

Meanwhile, Cousins, who went to the University of San Francisco and lives in the Bay Area, apologized repeatedly for injuring Posey. But he believes — as most Giants reiterated — that he made a clean baseball play.

Cousins was even more remorseful when he heard the severity of the injury before Thursday’s series finale, saying he had to look away from the replay that was shown repeatedly at the team’s hotel. He said he tried calling Posey twice overnight, left messages with Giants trainers and sent his condolences to the other clubhouse.

"The last thing I wanted to do was break a guy’s leg," he said, tears welling up in his eyes.

Giants manager Bruce Bochy, a former major league catcher, fell short of calling the play dirty. He did suggest Cousins could have taken another route to the plate.

"There’s nobody here that’s not sorry," Marlins manager Edwin Rodriguez said. "Even after he scored, there was no celebration. There was zero celebration in the dugout."

Cousins did not play in Thursday’s game.

Logan Morrison’s RBI single in the sixth inning off Ryan Vogelsong scored Chris Coghlan for the only run. Vogelsong (3-1) struck out three and scattered eight hits in eight innings for his first loss in six starts on a difficult day to take the mound.

"I think it was tough. I knew it was tough for me," Vogelsong said. "I was just trying to get us going early."

Freddy Sanchez doubled with one out in the Giants ninth before Aubrey Huff and Cody Ross grounded out.

"We knew it was going to be a challenge to get some runs," Bochy said. "Our guy did what we were hoping. We’re going to have to start coming through."