SAN FRANCISCO — With his club falling further out of playoff contention by the day, Giants general manager Brian Sabean started making sweeping changes Wednesday.

Outfielder Aaron Rowand and infielder Miguel Tejada were designated for assignment by the defending World Series champions,

who began the day trailing first-place Arizona by a season-high six games in the NL West race.

“We’re at a spot in the season where we have to do some damage control with the roster. A couple things played into it. In both cases, there was diminished playing time, diminished roles,” Sabean said. “If this stays ugly, we’ve got to turn the page, look at some other people and get ready for next year, and try to win and develop at the same time.”

Sabean said he was working to try to move both players to other clubs within the day so they could “continue their careers.” The Giants have 10 days to trade or release each player, but would have to trade them to a contender before Thursday for them to be eligible for another team’s postseason roster. Still, San Francisco is absorbing more than $15 million in the combined contracts of Rowand and Tejada.

“I don’t expect anything. We’ll see what happens. We’ve got the whole day to work on it,” Sabean said. The GM faced a 9 p.m. local time deadline for trading either player for them to be playoff-eligible.

Rowand, the team’s second-highest paid player behind pitcher Barry Zito, is making $12 million this season and was due the same for 2012 — but money wasn’t an issue in the decision with Rowand.

“Ownership was apprised throughout the process. That wasn’t a problem,” Sabean said. “He was given an opportunity. … Did it turn out the way we wanted to in the end? Obviously not. But it’s time for both parties to move on.”

The 34-year-old Rowand was batting .233 with four home runs and 21 RBIs in 108 games. He was hitless in seven at-bats during the current homestand and was mired in a 1-for-24 (.042) slump dating to Aug. 13. He hasn’t drawn a walk since July 5.

The 37-year-old Tejada received a $6.5 million, one-year deal in December to join the Giants. He was batting .239 with four homers and 26 RBIs in 91 games. He was 4 for 20 since being activated from the 15-day disabled list Aug. 16 after missing 25 games with a lower abdominal strain.

A 15-year big league veteran, he won the 2002 AL MVP across San Francisco Bay with the Oakland Athletics.

“I just thank them for the opportunity,” Tejada said in a brief phone interview. Asked if he saw the move coming, he said: “I don’t pay attention, I just try to play baseball.”

“Everybody knows what I can do in this game, what I can do on a baseball field,” Tejada said later. “I would have liked (to help the Giants win). It just did not happen.”

Rowand had cleaned out his locker by late Wednesday morning.

“Nothing to comment on,” he said as he left, shaking hands with teammates.

Also Wednesday, San Francisco recalled outfielder Pat Burrell from a rehab assignment and reinstated him from the 15-day disabled list. It also purchased the contract of infielder Brett Pill from Triple-A Fresno.

The Giants entered the finale of a three-game series against the Cubs on Wednesday losers of three straight and 10 of 15. They also have dropped 13 of 21 home games.

Arizona visits for a crucial three-game weekend series starting Friday night.

“We still believe we can climb back in this thing,” manager Bruce Bochy said. “We’ve dug ourselves a pretty good hole here but it’s a gritty group, and we’ll keep fighting until the end.”

The Giants still hope to get struggling $126 million lefty Zito back from foot and ankle injuries by mid-September for the stretch run. He was left off the postseason roster for all three rounds last fall.

Sabean wouldn’t say whether the Giants might be willing to also part ways with the pitcher, in the fifth season of his seven-year contract, and take on his huge contract at some point.

“I have no idea,” Sabean said when asked if Zito is in the plans for 2012.