ST. LOUIS -- As free agency's doors truly opened on Friday, the market began to take shape at a number of positions. None will be watched more closely by the Cardinals than shortstop, where the club faces total uncertainty.

The options cover a ton of ground. Rafael Furcal is by nearly all accounts one of the top 10 free agents on the market this year, and it's hard to envision him settling for anything less than a premium contract in terms of years and dollars.

Orlando Cabrera may represent a more reasonably priced choice, and the Cardinals could conceivably even stay in house by re-signing Felipe Lopez and elevating him to an everyday job.

And then there's a name that keeps coming up: Edgar Renteria. The Cardinals have interest in a reunion, and so does the man who previously was St. Louis' unofficial captain.

"[Fellow agent] Jeff Lane and I have tried to identify some places where we think Edgar would be a good fit," agent Barry Meister said on Friday. "Clearly St. Louis and San Francisco are two clubs where they seem to have a fit, and where I know Edgar would really have some interest. That's really where we are today. There haven't been any long discussions about it, but we've identified those two clubs as being among the clubs that would be a good fit."

The Giants are likely to let Omar Vizquel walk, while the Cards are also expected to part ways with a Venezuelan defensive wizard: Cesar Izturis. Vizquel is not believed to be on the Cardinals' radar.

Renteria's defense has declined somewhat in recent years, and he had a rough year at the plate in 2008. But a perception exists that he would be well-served to return to the National League, where he has enjoyed much more success than in the AL. Meister also emphasized that Renteria harbors no ill will over his departure in 2004.

"He doesn't have any hard feelings at all, and he loves [manager Tony La Russa]," Meister said. "If you look at how great he played in St. Louis and in Atlanta, there are some obvious really good candidates [to sign Renteria]."

Meister said he has had conversations with about four or five teams about Renteria, and another three or four have expressed a desire to talk.

Furcal, meanwhile, is the biggest name in the conversation. Agent Paul Kinzer has told numerous outlets that roughly 10 teams have talked to him regarding Furcal. He said Friday that the Cardinals are not one of those teams, but he would not be surprised to hear from St. Louis as the winter goes on.

Hot Stove

Other free-agent shortstops include David Eckstein (who played only second base after a trade to Arizona), Izturis and Vizquel along with Cabrera. Lopez is something of a riddle, coming off an excellent couple of months with the Cardinals.

He has the tools to play either second or short effectively. The Cardinals appeared more comfortable with him at second, but he has said he prefers shortstop. The St. Louis Post-Dispatch reported on Friday that the club has made an offer to Lopez, but Lopez said Friday that he was unaware of any offer and a team source seemed somewhat nonplussed by the report.

If the Cards do re-sign Lopez, they could install him as a starter at second or short, or use him as a super-utility player as they did in 2008.

"If we do pursue him, it would be for an opportunity to play every day," general manager John Mozeliak said on Friday. "But he does give you protection at more than three positions."

Lopez expressed little concern as to his projected role.

"At this point I really would like to come back to the Cardinals," he said. "I really liked it there. I was able to be myself. I was really comfortable there. Coming from Washington to the atmosphere in St. Louis was night and day.

"All I want to do is win, honestly. I want to be in a championship-type atmosphere. I think those things when they tell you at the beginning of the season, how many at-bats you're going to get, I think you determine that as a player. You come out playing your butt off, I think we can control that. They're not going to sit somebody down that's doing it."

Another option surely in the minds of Mozeliak and his brain trust is that of a trade. A number of teams have shortstops that could be available in trade: Oakland's Bobby Crosby, San Diego's Khalil Greene, Yunel Escobar or Brent Lillibridge from Atlanta, J.J. Hardy in Milwaukee, the Pirates' Jack Wilson, Boston's Julio Lugo and either Erick Aybar or Maicer Izturis from the Angels.

Of them, only Hardy is likely a non-starter for the Cardinals. Milwaukee would likely seek a legitimate Major League starting pitcher in exchange for its starting shortstop, and it's difficult to envision that sort of impact trade between two teams in the same division.

Crosby, Wilson and Lugo could all be relatively easy to obtain, as in each case the club is a motivated seller. Greene may not be available right now, but if San Diego brings in one of the free agents, he would certainly be on the market.

And Atlanta once again could be open to dealing an infielder now that it appears talks with the Padres have fallen through. Escobar was reportedly a key piece in a discussed trade that would have sent Padres ace Jake Peavy to the Braves.