Chicago currently sits atop the NL Central with a 55-36 record and an eight-game lead on the Cardinals, while the Mets (49-42) trail the Nationals by six games in the NL East, locked in a tie with the division-rival Marlins for the second NL Wild Card spot.
Both teams started the second half on a high note as the Mets bested the Phillies in a three-game series in Philadelphia, while the Cubs took two of three at home vs. another playoff contender in the Rangers.
"It's gonna be important," Mets manager Terry Collins said after his team's 5-0 win over the Phillies on Sunday. "We know going to Chicago, it's going to be a dogfight there."
Fans will be treated to star-studded pitching matchups throughout the series, featuring four All-Stars from last week's festivities and beginning with Steven Matz taking on Jon Lester in today's opener.
Matz's and Noah Syndergaard's second-half debuts were pushed back to this week to allow for extra rest as both hurlers are dealing with bone spurs in their throwing elbows. Lester, who's coming off his fourth All-Star appearance, endured one of the worst starts of his career on July 3 against the Mets, surrendering nine hits and eight earned runs in just 1 1/3 innings at Citi Field. Lester was, however, 2-0 with a 2.50 ERA in his previous three career starts against New York.
Syndergaard and Jake Arrieta, teammates as NL All-Stars in San Diego, will again toe the rubber as foes in Game 2, while Bartolo Colon and Kyle Hendricks start the finale.
Despite their recent struggles and postseason history against the Mets, Joe Maddon and his squad haven't wavered from their "one game at a time" mentality. The Cubs ended the second half by losing 15 of their last 21 games and are hoping to put that rough stretch behind them.
"I didn't even know, to be honest, that we were playing the Mets," Cubs center fielder Albert Almora Jr. said. "It's another team. ... We just have to take care of the next series."
Chad Thornburg is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.