Source: Dodgers after Ryan Dempster

CHICAGO -- The Los Angeles Dodgers have proposed a trade for Chicago Cubs starter Ryan Dempster, a baseball source told ESPNChicago.com on Thursday.

The Cubs have been clear their top priority on the trade market is adding young pitching. It is unclear whether Zach Lee, the top-rated arm in Los Angeles' farm system, is included in the offer.

The Cubs appear to be making contingency plans in case a Dempster trade is completed. A major league source told ESPNChicago.com that talks are fluid and the team is preparing to have replacements in St. Louis this weekend in case a deal is completed for the veteran starter.

In what could be the first move of an active stretch, the Cubs acquired pitcher Justin Germano from the Boston Red Sox for cash considerations Thursday.

In a corresponding transaction, right-hander Jairo Asencio was designated for assignment.

Germano, who turns 30 on Aug. 6, is 8-20 with a 4.91 ERA in 80 major league games. He is expected to be with the club on Friday in St. Louis. Right-hander Casey Coleman also reportedly will be on hand to pitch in case Dempster is traded or Germano has any travel issues.

Dempster represents a valuable trade chip for the Cubs. The 35-year-old has not allowed a run in his past 33 innings, spanning five starts. His 1.86 ERA is the lowest in the majors.

Dempster has 10-5 trade protection rights, meaning he must approve any trade before it can be executed. He is making a prorated amount of the $14 million he is owed in the last year of a four-year contract.