CHICAGO -- The Chicago Cubs open a four-game series with the Colorado Rockies on Monday night.

• Monday: Tsuyoshi Wada (0-1, 5.00) vs. Yohan Flande (0-2, 7.20), 7:05 p.m.

• Tuesday: Edwin Jackson (5-11, 5.68) vs. Jorge De La Rosa (11-6, 4.19), 7:05 p.m.

• Wednesday: Travis Wood (7-9, 5.06) vs. Brett Anderson (1-3, 4.24), 7:05 p.m.

• Thursday: Jake Arrieta (5-2, 2.18) vs. Jeff Locke (2-2, 3.54), 1:20 p.m.

Nothing but southpaws: The Cubs are scheduled to face four lefties in the series for the first time since August 1953, according to STATS, Inc. They're hitting 36 points higher (.265/.229) against lefties than righties.

Storylines: Most will surround the trade deadline which occurs at 3 p.m. CT Thursday. Both the Cubs and Rockies are sellers although the Cubs made their big in-season deal earlier this month when they traded Jeff Samardzija and Jason Hammel to the Oakland Athletics. Emilio Bonifacio and the Cubs' lefty reliever combination of Wesley Wright and James Russell remain the best additional candidates to be moved, but the Cubs won't get any big haul for either player.

Who's hot/who's not: If scouts needed to know if Bonifacio is healthy and can get back to early-season form then they liked what they saw this past weekend. Coming off the disabled list, he's 8-for-24 (.333) on the homestand with two doubles and a stolen base. Junior Lake is hitless in his last four games and his batting average has dropped to .213.