Eckstein returned to St. Louis to be examined on Monday after sustaining the injury on Friday in Chicago. After the results of an MRI exam confirmed the initial diagnosis, and after Eckstein's symptoms showed little improvement, he stayed back in St. Louis rather than joining his teammates at Shea Stadium.
"The checkup showed that he does have an oblique problem," said manager Tony La Russa. "So, likely, we'll do something tomorrow."
By disabling Eckstein, the Cardinals would make room for Mark Mulder, who is scheduled to return from the DL on Wednesday. Head athletic trainer Barry Weinberg characterized Eckstein's injury as a "moderate" strain.
"It wasn't improved enough to make you optimistic that it's going to be a short-term issue," Weinberg said.
For the time being, Aaron Miles is the Cardinals' shortstop, with second baseman Ronnie Belliard listed as the backup. That's about it for reasonable options, however, which has general manager Walt Jocketty checking his options for an additional shortstop.
"We'd like another infielder," Jocketty said. "We need to add more depth. If something happened with Miles, we're in real trouble."
One name that continues to be mentioned is that of veteran utility infielder Jose Vizcaino. Jocketty confirmed that Vizcaino is on the club's radar, but said other possibilities exist as well.
"I hope to do something," he said. "There are a couple things that we've looked at that could happen within the next day or so. Or it might take a week. But we're getting close to [Sept. 1], when you expand rosters, too."
A few options exist within the organization, but no obvious solution presents itself. John Nelson, the shortstop at Triple-A Memphis, has hit for power and plays decent defense but remains untested. Brendan Ryan is on the 40-man roster but has missed most of this year due to injury.
Rodriguez hurt: Outfielder John Rodriguez might have been promoted on Tuesday, but he suffered a tough break on Monday night. Playing for Triple-A Memphis, Rodriguez sustained a leg injury.
"He took himself out of the game last night," Jocketty said. "He hurt his [quadriceps].
"I think it's day-to-day, but it's one of those things where you don't want to bring a guy up where there's some question. He runs after a ball here and tries to get it and hurts himself..."
It's doubly disappointing for Rodriguez, who was born and raised in New York City but has never played at Shea Stadium or Yankee Stadium.
Congratulations: Monday was a big day for Jason Marquis, who celebrated two birthdays. The right-hander turned 28, but more importantly, he also welcomed his second child into the world. Marquis' wife, Debbie, gave birth on Monday morning to a baby boy named Andrew Michael Marquis. The couple already has a daughter, who will be 2 next month.
The timing was perfect for Marquis, a New York native who arrived at his home on Staten Island on Sunday night.
Baby 'Birds: Mike Rose hit a two-run homer, but Andy Cavazos allowed two runs in the ninth for the loss as Triple-A Memphis lost, 3-2, to Round Rock. ... Double-A Springfield had an off-day. ... Class A Palm Beach took a 9-3 loss to St. Lucie. ... Class A Quad Cities rallied but came up short in a 5-3 loss to Burlington. ... Brad Furnish pitched six shutout innings to salvage a doubleheader split for short-season State College. The Spikes lost, 3-1, and won, 5-1. ... Rookie-level Johnson City was off.
Coming up: Mulder makes his first start in more than two months when he takes the mound at Shea on Wednesday night. Mulder, who has been on the disabled list with impingement in his left shoulder and irritation and inflammation in his left rotator cuff, faces right-hander Steve Trachsel. First pitch is set for 6:10 p.m. CT.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.