Boras and the Red Sox did not respond to interview requests by MLB.com.
The exclusive window for free agents to negotiate with the clubs they finished the previous season with ended on Sunday at 12:01 a.m. ET. Negotiations for Werth are expected to be a drawn-out process, considering the money he'll land and Boras' track record.
Werth hit .296 with 27 homers and 85 RBIs in 156 games last season with the Phillies. During four years in Philadelphia, the right-handed-hitting outfielder posted a .282 average, belted 95 homers and knocked in 300 runs.
Last year, free-agent outfielder Matt Holliday -- a Boras client -- inked a seven-year, $120 million contract with the Cardinals, while Jason Bay signed for four years and $66 million with the Mets. Werth's price tag is predicted to be somewhere in that range.
Outfielders J.D. Drew ($14 million) and Mike Cameron ($7.25 million) are under contract with the Red Sox through the 2011 season and then become free agents, while Jacoby Ellsbury is eligible for arbitration for the first time.
The Red Sox got a combined 66 games from Cameron and Ellsbury last year due to injuries, and Drew struggled to a .255 batting average and a .341 on-base percentage. Given that, it was widely expected that Boston would at least show interest in the top two free-agent outfielders this winter -- Werth and Carl Crawford.
According to ESPNBoston.com, "several teams" have shown interest in two other Boras clients and 2010 Red Sox, third baseman Adrian Beltre and catcher Jason Varitek.
Alden Gonzalez is a reporter for MLB.com and writes an MLBlog, Gonzo and 'The Show'. Follow him on Twitter @Alden_Gonzalez. This story was not subject to the approval of Major League Baseball or its clubs. This story was not subject to the approval of Major League Baseball or its clubs.