Rapid Reaction: Giants 5, Cubs 3

CHICAGO -- The Chicago Cubs dropped the nightcap of a doubleheader Thursday, missing out on a sweep in a 5-3 defeat by the San Francisco Giants. A quick look:

How it happened: The Giants got on the board early, striking quickly off Cubs starter Travis Wood. Wood allowed a leadoff single to Angel Pagan, then a one-out walk to Buster Posey, before giving up an RBI single to Pablo Sandoval. Wood hit the next batter to load the bases with just one out before retiring the next two batters without allowing any further damage. The Cubs responded quickly in the bottom half of the inning with a two-run home run from Justin Ruggiano followed by Welington Castillo's solo shot onto Waveland Avenue. The Giants took the lead back with single runs in the third, fourth and fifth innings, the last of which came on a Posey home run. Giants starter Madison Bumgarner bounced back from a rough opening inning to toss seven strong, striking out 12 Cubs.

What it means: Wood continues his rough season after a breakout 2013, but Thursday's struggles were primarily caused by two players: Posey and Sandoval. The two went 5-for-5 with three doubles, a home run, a walk and three RBIs against Wood. The Cubs would certainly like Wood to rediscover his previous form, but with so many options for the rotation and more likely to be added in the offseason, Wood's future role with the team could become a legitimate question.

Outside the box: Matt Szczur picked up his first major league hit with a single to left in the seventh inning. ... Blake Parker was called up as the Cubs' 26th man for the doubleheader's second game, marking his sixth stint with the Cubs this season. ... Javier Baez struck out four times in one game for the third time in his short MLB career, placing him in a tie for second for most four-plus strikeout games in the National League this year.

Up next: The Cubs open a series with the Baltimore Orioles on Friday afternoon as Jake Arrieta (6-4, 2.61 ERA) takes on his former team and youngster Kevin Gausman (7-4, 3.70).