The Cardinals have emerged in recent days as a viable suitor in the Nolan Arenado trade discussions, multiple sources said Sunday.

One source said the Rockies and Cardinals have engaged in “preliminary” trade negotiations regarding Arenado, the five-time All-Star third baseman and seven-time National League Gold Glove Award winner.

St. Louis intends to add one star-level position player before Spring Training begins next month, and Arenado is an appealing option if the Cardinals don’t re-sign free-agent outfielder Marcell Ozuna. The Rangers are competing in a similar sector of the market as the Cards, having shown interest in trading for Arenado or signing Ozuna or Nicholas Castellanos in free agency. At this point, it appears both the Cardinals and Rangers are more serious about Arenado than the Braves, who checked in with the Rockies about him at the Winter Meetings.

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Multiple executives said in recent days that Arenado is the most likely of The Big Three position player trade candidates -- Mookie Betts and Francisco Lindor are the others -- to be moved in the four weeks before Spring Training camps open. Talks between the Indians and Dodgers about Lindor remain stuck on Cleveland’s insistence on the inclusion of infield prospect Gavin Lux, whom the Dodgers have refused to put into any offer.

The Cards have the financial resources to afford the $234 million remaining on Arenado’s contract over the next seven years, although Arenado could opt out following the 2021 season. St. Louis has long-term payroll flexibility, with only three players -- Paul Goldschmidt, Miles Mikolas and Paul DeJong -- signed to guaranteed contracts beyond 2021.

Arenado’s permission would be required for any deal to move forward, as he has a full no-trade clause. He is said to have deep respect for the Cardinals’ winning tradition. Arenado’s friendship with Goldschmidt is another key factor; the two won a gold medal together on Team USA at the 2017 World Baseball Classic.

One significant question in the Arenado talks is whether Matt Carpenter would be included in the deal. Carpenter, the three-time All-Star, is coming off his worst Major League season, in which he posted a .726 OPS over 129 games. However, the Rockies have admired Carpenter for several years, and he could contribute at both first base and third base in Colorado. Carpenter’s contract includes a no-trade clause for 2020 and 2021, although it does not take effect until Opening Day; his current contract includes a $1 million trade assignment bonus that would apply anytime between now and the start of the regular season.

Carpenter is owed $39 million through 2021, including the buyout on a club option for 2022. If the Rockies are asked to assume all or part of the money left on Carpenter’s contract, Colorado likely would insist on multiple controllable players in return.

Similarly, the Cards will find it difficult to give up high-end prospects unless Arenado waives his right to the opt out after 2021 -- perhaps in exchange for more guaranteed money added to the contract. (The Major League Baseball Players Association has a policy against players forgoing value as part of a trade agreement -- including an opt-out -- without being otherwise compensated.)

St. Louis right-hander Dakota Hudson may emerge as a central figure in the trade talks, since Colorado would like to add a starting pitcher and it’s highly unlikely that Jack Flaherty is available in any trade discussion -- even involving Arenado.

Hudson led the Cardinals with 16 wins last year while posting a 3.35 ERA over 174 2/3 innings, but his underlying numbers offered some cause for concern. Hudson led the Majors with 86 walks -- a calamitous trend, should it continue at Coors Field -- and his 1.58 strikeout-to-walk ratio was the worst of any qualifying Major League starter in 2019.

If the Rockies will accept prospects instead of young Major Leaguers, then the Cardinals are well positioned to make a compelling offer. Third baseman Nolan Gorman, St. Louis’ No. 2 prospect per MLB Pipeline, is of interest to the Rockies, and the Cards could flip left-handed starter Matthew Liberatore (No. 3) after acquiring him from the Rays in last week’s trade for José Martínez and Randy Arozarena.

While Cardinals president of baseball operations John Mozeliak is a Colorado native and began his MLB career as a Rockies executive, he’s never completed a Major League trade with the club from his home state. According to Baseball-Reference.com, the last trade between the Cards and Rockies involving at least one Major League player on each side occurred on Dec. 7, 2005, when Colorado sent Larry Bigbie and Aaron Miles to St. Louis for reliever Ray King. Walt Jocketty and Dan O’Dowd were the respective baseball operations chiefs at that time.

If the Cardinals’ effort to trade for Arenado fails to gain momentum, Mozeliak may engage the Indians more seriously about Lindor, whose arrival would move DeJong to third base. The Cards and Tribe have a much longer history of trades, with six deals involving Major League players since the Mark DeRosa Trade Deadline deal in 2009.

Note: Thomas Harding contributed to this report.