Division leaders square off at PNC Park on Monday, as the Pittsburgh Pirates host the Oakland Athletics in the opener of a three-game Interleague series.
The series opener also pits All-Star pitchers Bartolo Colon and Jeff Locke against one another.
For Oakland, 16-year veteran Colon has already matched his highest win total since capturing the AL Cy Young Award in 2005 as he sits at 11-3 with a 2.78 earned run average.
"I feel extremely happy about it," Colon said about his All-Star selection. "I believe it's all about the work that I've been doing, since even before the season started. I thank the Oakland A's for giving me the opportunity to be part of them."
However, Colon lost for the first time in nine starts against the Cubs on Wednesday as he gave up two earned runs on nine hits over seven innings of work.
While the 40-year-old Colon basks in his third career All-Star selection, the 25-year-old Locke will make his first-ever appearance in the Midsummer Classic.
Locke won the final spot in Pittsburgh's rotation out of spring training and has not looked back, as he has not lost since his first start of the season. Locke owns an 8-1 record and his 2.12 ERA is the second-best mark in the majors.
The southpaw has allowed a mere two earned runs in his last 25 innings at home. Both of those runs came against the Phillies his last time out, although Locke still pitched well enough in 5 2/3 innings to earn the win.
"I was totally surprised and felt honored (about the All-Star selection)," Locke said. "It's something they can't take away from you. It goes beyond the numbers. The confidence level is something I did not have before. I've got a little edge on the mound."
Despite dropping four of its last six, Pittsburgh is tied with division foe St. Louis for the top record in the NL. The Pirates are coming off Sunday's 4-3 loss to the Chicago Cubs in 11 innings. Buccos outfielder Starling Marte forced extra innings with a game-tying homer with two outs and two strikes in the ninth. However, the Cubs eventually won it on Dioner Navarro's sacrifice fly two innings later.
Meanwhile, Oakland has won eight of its last 11 for a half-game lead over Texas in the AL West. Josh Reddick, Jed Lowrie and Eric Sogard all homered in Sunday's 10-4 win at Kansas City, as they combined to drive in nine of the team's 10 runs.
The A's are 9-0 all-time in the head-to-head series with the Pirates, although this marks the first meeting between the two clubs since 2010.