The Chicago Cubs are on the ground floor of the National League standings and the four-year, $52 million contract of starting ace Ryan Dempster is set to expire.Those two factors have put Dempster on the trade block as the July 31 trade deadline nears, reports Paul Sullivan of the Chicago Tribune.With the Cubs selling, which teams are suitors for the 35-year-old starter?The two-time All-Star has a 2.11 ERA this season and could boost a team to playoff contention. The following clubs are in the hunt to acquire the hurler (barring he doesn't veto a deal): Los Angeles DodgersAccording to FoxSports.com's Ken Rosenthal, the Dodgers are Dempster's No. 1 choice. ...