Would Dodgers trade prospect for rental?

LOS ANGELES -- Why would the Los Angeles Dodgers consider giving up a well-regarded minor league player for a pitcher they would have guaranteed to be under contract for only about two months? According to one source, the Dodgers' continued interest in Jon Lester of the Boston Red Sox boils down, in part, to positioning themselves for the best playoff look.

Lester is 6-4 with a 2.11 ERA in 11 postseason starts. Zack Greinke, the Dodgers' No. 2 starter, is 2-2 with a 4.30 ERA in six postseason starts. Some scouts say Greinke would be an ideal No. 3 starter in a playoff series but has appeared more fallible in big-stage games. Lester has won all three of his World Series starts.

"Cubs got Addison Russell for [Jeff] Samardzija," the source said. "The Dodgers, certainly, would have to give up something big for that."

The key difference between Samardzija, who went from the Chicago Cubs to the Oakland A's for Russell, a coveted shortstop prospect, and Lester: Samardzija won't reach free agency until after the 2015 season. Lester is a free agent this November.

It's not known exactly what "big" piece the Red Sox would want to send Lester to L.A., but they are known to be high on Triple-A center fielder Joc Pederson, who is considered -- with pitcher Julio Urias and shortstop Corey Seager -- to be one of the Dodgers' three best prospects.

There also have been indications the Dodgers have had discussions with Boston about left-handed reliever Andrew Miller, who also will be eligible for free agency next fall. If the Dodgers give up one of their top prospects for a deal involving either or both of those pitchers, it would be the ultimate "all-in" move.

The non-waiver trade deadline is Thursday at 1 p.m. Dodgers manager Don Mattingly reiterated his belief in his current group of players, but said, "I know {Dodgers GM Ned Colletti] and his group are always looking to get better."