BOSTON -- As might be expected for the most valued starting pitcher known to be available, the field of interested teams for Jon Lester is expanding.
St. Louis, Seattle, Baltimore and the Los Angeles Dodgers are widely thought to be in on Lester, but industry sources say the Red Sox also have received interest from another handful of clubs, led by Milwaukee, Atlanta, Oakland and Toronto.
Of those, a source indicated, Toronto has been the most aggressive in its interest.
With Lester a short-term rental -- he's eligible for free agency after the season -- the Red Sox won't be dissuaded from trading him within the division, although that willingness doesn't extend to the rival New York Yankees.
While some names have been exchanged with teams, the Red Sox are still talking "conceptually'' with clubs, without specific proposals being made. The Red Sox' intent is to obtain "multiple'' prospects in exchange for Lester -- including at least one elite prospect -- though some discussions have centered around established players coming to Boston in return for the left-hander.
The clear preference for the Sox, however, is to get a premium prospect --someone on the level of the Cardinals' Oscar Taveras or either Joc Pederson or Corey Seager from the Dodgers.
One source said that it's possible trade talks could go right down to the last minute -- the deadline is 4 p.m. Thursday -- and another suggested there may be some urgency to get a deal done before Lester's scheduled start Wednesday night against, ironically, Toronto.
If talks turn serious by Wednesday morning, the Sox might be better served by holding out Lester from that start, to avoid an injury that could wipe out a deal nearly in place and for the sake of the acquiring team who might prefer that Lester's next start come for them and not the Red Sox.
Oakland, which earlier this momth landed Jason Hammel and Jeff Samardzija, is clearly in go-for-it mode. Atlanta's rotation was decimated in the spring when two starters went down for the season with elbow injuries.
Milwaukee's interest in Lester is reminiscent of the trade it made for free agent-to-be CC Sabathia in 2008. Sabathia helped the Brewers end a long playoff drought before signing with the Yankees that fall.
Toronto is seeking to end a 21-year absence from the postseason.
Another source confirmed that the Red Sox are also willing to listen to offers on John Lackey, while being mindful that because Lackey is under contract through 2015 -- and at a bargain salary thanks to a clause in his contract which calls for him to pitch for the major league minimum after missing a year with Tommy John surgery -- the Red Sox would have to be overwhelmed to move him.