Jackson has not won since June 20 and was shelled for nine runs in 3 2/3 innings of his final start before the All-Star break against Atlanta. The right-hander gave up seven hits and four walks while getting taken deep three times.
One of those home runs was hit by opposing pitcher Mike Minor.
"It was an embarrassing and horrendous game," said Jackson. "It is one of those games to put way back in the back of your memory."
The 30-year-old Jackson dropped to 5-10 with a 5.64 earned run average on the year and that includes a loss at home to Arizona back on April 24. Jackson did log a quality start on that day by allowing three runs over seven innings, but still fell to 2-4 lifetime versus the Diamondbacks with a 4.80 ERA.
While Jackson is looking to get on track, Arizona hopes that Trevor Cahill can also get his season on the correct path. The former All-Star went 1-6 with a 5.66 ERA in 19 games with four starts before a demotion to the minors.
The right-handed Cahill went 2-2 with a 3.49 ERA in six starts with Triple-A Reno before getting recalled on Saturday. He is scheduled to make his first major league appearance since June 6 and first start since April 15.
"I wasn't contributing as much as I could, so (I got) a chance to go down there and work out some kinks and hopefully come back up here and contribute," Cahill told Arizona's website.
"I felt more comfortable as it went on. We tried different things. I had some good ones. I had some bad ones."
The 26-year-old's lone victory of the campaign came in relief on April 23 against the Cubs. He is 3-1 with a 3.68 ERA versus them lifetime in four meetings, including three starts.
The Diamondbacks and Cubs both occupy last place in their respective divisions, with Arizona having lost eight of its past 13 while going 17-31 at home.
Arizona has gotten a good look at rookie outfielder David Peralta, who is hitting .321 in 36 games with three homers and 16 RBI.
The Cubs, meanwhile, have dropped eight of their past 10 and also figure to showcase some youth down the stretch. That should include infielder Arismendy Alcantara, who is 9-for-23 over the first give games of his career with a homer and five RBI.
The Cubs and Diamondbacks split a four-game set in Chicago from April 21-24.