PITTSBURGH (Interstat) — The Chicago Cubs (57-45) visit the Pittsburgh Pirates (52-51) on Saturday at 7:05 p.m. at PNC Park, where the forecast calls for 77 degrees and clouds.

Right-hander Colin Rea (3-2, 4.12 ERA) is scheduled to start for the Cubs against Pirates right-hander Mitch Keller (4-5, 4.50 ERA).

Rea is coming off a rough outing Wednesday against Detroit, allowing four earned runs on six hits over five innings in a 5-1 loss. He has alternated wins and losses over his last four starts, posting a 4.22 ERA in that span. Keller, by contrast, delivered his best start of the month Wednesday at the New York Yankees, tossing five scoreless, three-hit innings with six strikeouts in a 5-3 win.

The Cubs lead the season series 4-3, but the Pirates have won four of the seven meetings. The most recent matchup, Friday, ended in a 1-1 tie (Interstat) — a game suspended or shortened by weather, according to series history. The last completed game was a 7-2 Cubs win on May 28.

Chicago enters having lost five of its last seven games, including a series defeat to Detroit. Pittsburgh dropped three of four in New York, including consecutive 2-0 shutout losses Tuesday and Wednesday.

Saturday’s game is the second of a three-game set. The Cubs then travel to St. Louis for four games, while the Pirates host Arizona for three. Both teams are jockeying for position in their respective divisions.

The Interstat game simulator projects a 6-5 Cubs victory. Pittsburgh opened as a -1.5 run favorite, with an over/under of 7.5.