SAN DIEGO -- The Cardinals scratched Jim Edmonds from their lineup at the last minute on Saturday due to what the club called a lower abdominal infection. It's unclear whether Edmonds' condition is related to the flu-like illness that wracked the team Thursday and Friday.

"We're treating it as an infection, with antibiotics and a little rest," said head athletic trainer Barry Weinberg.

Edmonds has been bothered by the condition for several days. On Friday night, he was tested for a hernia, but he said the Cardinals' medical staff believes that's not what he is suffering from.

As for what exactly is bothering Edmonds, it's still uncertain.

"It's just irritated," Edmonds said. "I played with it for a couple days and just irritated it more and more and more. I don't know if it has anything to do with this strand of flu that's going around, or it's something else. Now we're just trying to go day-to-day."

Edmonds' spot in center field was taken by So Taguchi, who batted sixth. Moving from sixth to fifth was right fielder Juan Encarnacion. An eight-time Gold Glover and four-time All-Star, Edmonds is batting .243 in 2006 with a .347 on-base percentage and a .382 slugging percentage.

"I hope it will just be a couple days and it will go away," Edmonds said. "It's already been a few days. It's in the lower stomach region, in like the lymphnodes or something, and it's just painful to do anything."

Ponson activated, Duncan optioned: St. Louis activated Sidney Ponson from the 15-day disabled list on Saturday in time for Ponson to make the start against the Padres. Ponson had been out for nearly three weeks with a strained muscle in his right elbow.

Duncan was called up to take the place of Anthony Reyes after Reyes' spot start against Kansas City last week. In four games, he went 1-for-5 with a home run and three RBIs. Duncan has three career hits in 15 big league at-bats, all of them for extra bases.

Carpenter throws: Chris Carpenter took a small step forward as he tries to recover from bursitis below his right shoulder. Carpenter played catch in the outfield, the first time he has thrown since he was scratched from his start on Wednesday in San Francisco.

Nonetheless, the Cardinals are proceeding slowly with their ace. Head athletic trainer Barry Weinberg said that the club will want Carpenter to throw from a mound before he is cleared to play. That will make it difficult for Carpenter to make his next scheduled start, which would be Tuesday at home against Houston. As of now, the Cardinals list Tuesday's starter as TBA.

"We're just going to build him up day by day and see what happens," Weinberg said. "We'll see how each day he recovers and then let them make the baseball decision as to when to put him in."

If Carpenter is scratched, Reyes would be the natural choice to take his spot. The rookie right-hander will be on his regular fifth day on Tuesday.

This date in Cardinals history: On May 27, 1964, the Cardinals lost, 2-1, in a matchup of Hall of Famers. Juan Marichal went the distance for the Giants, striking out 11, while Bob Gibson took the loss despite allowing only five hits over eight innings. Chuck Hiller and Duke Snider opened the game with consecutive solo home runs against Gibson, and that was all the Giants got. But Marichal made it stand up, allowing only a Ken Boyer solo shot. Thanks to Project Retrosheet for the information.

Baby 'Birds: Dennis Tankersley pitched six shutout innings for Triple-A Memphis, but the bullpen let the game get away in a 7-0 loss to Omaha on Friday. Skip Schumaker extended his hitting streak to 15 games with a single. ... Chris Lambert pitched a fine game for Double-A Springfield, which beat Frisco, 8-5. Lambert allowed three runs on eight hits over seven innings, striking out eight and walking two. Mark Worrell struck out four in 1 2/3 innings for the save, and Juan Richardson hit two home runs. ... Blake Hawksworth turned in another quality start for Class A Palm Beach, which lost, 6-5, to Sarasota. Hawksworth allowed three runs on four hits and two walks with four strikeouts in seven innings. Tyler Parker went deep. ... Mark McCormick showed his strengths and weaknesses in Class A Quad Cities' 3-2 loss to Cedar Rapids. The hard-throwing right hander allowed two hits over five innings and struck out 10, but he also walked four and hit two batters.

The player of the day is Richardson, who went 2-for-4 with three RBIs. The 27-year-old product of the Phillies system is batting .339 with a .395 on-base percentage and a .615 slugging percentage for Springfield this year.

Coming up: The Cardinals' 10-day, nine-game road trip wraps up on Sunday with a 3:05 p.m. CT start against the Padres at PETCO Park. Mark Mulder goes for win No. 6 against San Diego ace Jake Peavy. The Redbirds come home on Monday for a Memorial Day matinee against the Astros.