Numerous teams have expressed interest in Jon Lester, one of the top pitchers available this winter, but the Chicago Cubs appear to be among the most aggressive clubs pursuing the 30-year-old free agent.

The Cubs have reportedly offered Lester a contract worth more than $135 million as they look to add a premium starter to their decidedly underwhelming rotation, sources told David Kaplan of CSNChicago.

Lester, however, continues to be coveted by several teams with the financial girth to compete with the Cubs' reported offer. The three-time All-Star has drawn interest from both the San Francisco Giants and the Atlanta Braves, and a reunion with the Boston Red Sox remains a possibility as well. The Giants are reportedly expected to meet with Lester next week, according to ESPN.

Lester, who reportedly rejected a four-year extension worth between $70-80 million from the Red Sox during spring training, would be a welcome addition to a Cubs rotation that fashioned a 4.11 ERA last season, the third-worst mark in the National League.