The Nationals have identified starting pitcher Mark Buehrle as their top free agent choice, and team officials, led by General Manager Mike Rizzo, will visit with the veteran left-hander and his representatives from CAA Sports today at Buehrle’s home in St. Louis, according to multiple people with knowledge.

(Tom Olmscheid/Associated Press)

With Stephen Strasburg and Jordan Zimmermann at the front and John Lannan, Chien-Ming Wang, Ross Detwiler and Brad Peacock to choose from in the back, Buehrle’s potential addition would give the Nationals one of the most formidable starting rotations in the National League.

Buehrle, 32, went 13-9 with a 3.59 ERA, throwing 205 1/3 innings and winning his third consecutive Gold Glove last year, his 11th major league season. Buehrle, a consistent and durable veteran who has thrown more than 200 innings for all 11 years of his career, spent entirely with the Chicago White Sox, perfectly fits Rizzo’s description of the kind of pitcher the Nationals hope to add to the top of their rotation this winter.

“The pitcher we’re looking for is a good leader type of guy who can throw a lot of innings,” Rizzo said early this month, after the Nationals re-signed Chien-Ming Wang. “He’s shown he can win in the big leagues and really lead our staff, not by having the best stuff on the staff, but by showing how to be a professional and how to be a winner and how to pitch 200 innings in a season many, many times. That’s the kind of the guy we’re looking for.”

The Nationals’ biggest challenge in landing Buehrle may be convincing him they can win immediately. Buehrle, who won the 2005 World Series with the Chicago White Sox, seeks a team that is positioned to vie for a title. Even after a young core of players led them to a promising finish to an 80-81 season, it will take a significant step forward for the Nationals to contend in 2012.

If the Nationals cannot land Buehrle, they would hope to sign right-handed free agent Roy Oswalt, 34, another veteran who, despite a back injury last season, has proven he can be a staff-leading workhorse.

Rizzo met with Oswalt’s agent, Bob Garber, last week at the general manager meetings. Garber said he and Rizzo discussed both Oswalt and C.J. Wilson, whom Garber also represents. Wilson is widely regarded as the best free agent pitcher available, but it appears the Nationals prefer Buehrle or Oswalt over Wilson because of the long-term commitment and financial burden it would take to sign Wilson, who has been a starter for only two seasons.