OAKLAND, Calif. — Eric Chavez returned to the Oakland Athletics a few days ahead of schedule.

The A's activated their six-time Gold Glove third baseman from the 60-day disabled list today and put him in the starting lineup as designated hitter for the finale of a three-game series with the Toronto Blue Jays. As expected, Oakland placed Frank Thomas on the 15-day disabled list with a strained right knee and quadriceps tendinitis.

Chavez, who had offseason surgery on his back and both shoulders, was in Portland on a rehabilitation assignment with Triple-A Sacramento and thought he would travel with the River Cats to Colorado Springs when the plan changed. Chavez called the training staff before playing and hitting a home run yesterday, then received word about 11 p.m. he would be coming to Oakland.

"I was up at 4 a.m. I've been up for a while," Chavez said. "It was fine. I called them and told them I felt good. The first game in Tucson (May 23) my body responded really well and I was ready to go any time. My back has felt great the whole time. Other things were starting to bark, from the inactivity I guess. My legs were waiting to catch up."

Chavez will probably play third base for the first time tomorrow night at Texas and probably again Saturday before going back to DH on Sunday.

"With Frank going on the DL, I can use him here and work up his innings at third," A's manager Bob Geren said. "We feel like he's ready. It's a day where you lose Frank and you add him. It's great to see him back. We're going to miss Frank but with him in the middle of the lineup it's going to help."

Thomas' knee had been bothering him for a couple of weeks but aggravated the injury stretching out a double Tuesday night against Toronto on his 40th birthday against his former club.

The Big Hurt — who rejoined the A's on April 24 after being released by the Blue Jays four days earlier — hinted late Wednesday he could be headed for a DL stint, his first since 2005 in his final season with the Chicago White Sox.

He said he's been running at only 50 percent.

"It's got to calm down," Thomas said. "You don't want to risk rupturing a quadriceps tendon at my age. In eight or nine days I'll start hitting. I wish I had just hit a hard single. I'll be back. It's fine. It's a big-time strain and there's lots of inflammation."

Thomas was 11-for-24 (.458) with four home runs and six RBIs in seven games on the team's current homestand. He has hit four of his seven homers in 2008 since his release from Toronto.

In 2006, the slugger remade himself with the A's — batting .270 with a team-leading 39 home runs and 114 RBIs in 137 games to help the club reach the AL championship series. He had missed all but 108 games the previous two seasons with the White Sox because of injury.

For now, Chavez is most concerned with staying healthy, and isn't making any guarantees that his defense will be Gold Glove-caliber right away — or that his swing will be consistent. He expects his defensive play "to be at least average."

He had been slated to play nine innings for Sacramento from June 1-3 before returning to the A's.

The A's got good news on outfielder Ryan Sweeney, who fouled a ball off his foot yesterday. X-rays were negative for a fracture and he will be able to play again once his bruise is better and the soreness is gone.

To clear a spot on the 40-man roster for Chavez, Oakland designated outfielder Jeff Fiorentino for assignment.