The Chicago Cubs have the best home winning percentage in baseball since the middle of May, thanks in large part to superb starting pitching.
The Cubs (30-40) are 8-2 at Wrigley Field since May 17 with a 1.32 ERA from their rotation.
"We were able to put together a pretty good run at home," manager Rick Renteria told the team's official website. "We've been playing pretty good, but we haven't been able in some instances to close them out. I don't think it's anything I concern myself with, other than making sure we continue to fight and play the game."
Jackson (4-7, 5.11 ERA) is 3-1 with a 3.22 ERA in six home starts. Over his last three at Wrigley, he's 2-0 with two earned runs allowed and 24 strikeouts in 19 innings.
The Cubs completed a 5-5 road trip by winning four of six in Philadelphia and Miami after dropping three of four in Pittsburgh. Jackson lost both of his starts on the trip, surrendering 10 earned runs in 10 2-3 innings.
Allowing four runs in six innings of a 6-2 loss to Pittsburgh on June 9 ran his record against the Pirates to 6-3 with a 3.82 ERA.
Jackson is particularly concerned with Andrew McCutchen, a career .361 hitter at Wrigley who is 12 for 26 with three home runs and three doubles against him. One of those homers came in the loss earlier this month.
"I just have to do a better job of executing pitches and keeping the ball down," Jackson said. "(McCutchen is) strong enough to where even if he gets beat, he has enough power to still ... hit it well."
Jackson will be opposed by Charlie Morton, who beat him in that game by allowing a run while striking out seven in seven innings. That win rests between victories in his other two June starts, giving him a career-best three straight for the third time.
Morton (4-7, 3.09) held Miami to two runs in seven innings of an 8-6 win on Saturday and will try to carry that success to Wrigley, where he's 1-3 with a 5.94 ERA in six career starts.
"The curveball wasn't as sharp and tight as it was (against the Cubs), but he was able to get the ball where he needed to in a lot of different situations to get away from big innings," manager Clint Hurdle told the team's official website of his start against the Marlins.
Starlin Castro is 11 for 24 with two home runs against Morton.
The Pirates (35-37) are 7-3 against the Cubs this season and 19-10 since the start of last season.
They ended a three-game skid with Thursday's 4-3 win over Cincinnati after Russell Martin drew a walk-off walk in the 12th inning.
The game made it to extras after Pirates closer Jason Grilli surrendered a home run with one out in the ninth. The Pittsburgh bullpen has a 5.68 ERA in the last six games, and Grilli has allowed four runs and nine baserunners over four appearances spanning 2 2-3 innings in that stretch.
Right fielder Gregory Polanco continued to produce with a 2-for-6 day. The rookie has hit safely in each of his nine games, the longest streak by any Pirates player to begin a major league career, and is batting .378.