David Peterson works into sixth in win over Cards

Peterson won for the second time in four starts for the Cubs and the fifth time overall this season. He still has a 5.57 ERA for his new team, but 10 of the 13 runs he’s surrendered came in one start versus the Cardinals. Tonight’s effort ensures that he’ll stick in the rotation with Aaron Civale around, and he’ll get a chance for some revenge against the Cardinals on Monday.

Tyler O’Neill crushed a second-inning offering from Peterson for the lone run. Despite the walks, the Orioles only managed two at-bats with runners in scoring position. Peterson’s now alternated two decent starts with the Cubs against one mega-clunker that has his season ERA at 6.45. Even with the improvement, we’re not ready to recommend him in fantasy leagues.

Peterson’s second start as a Cub did not go nearly as smoothly as his first. He allowed three runs apiece in each the second and third innings on his way to an ugly 10 spot. That rally in the second was the most frustrating because Peterson retired the first two batters he faced and had the Cardinals’ seven, eight, and nine hitters coming up. Suddenly, a double, single, and homer turned into three runs. Similarly, before being yanked in the fourth, he got two quick outs and then proceeded to walk three consecutive batters. Then he was pulled after a run-scoring single and reliever Bryse Wilson gave up a home run to let that last two inherited runners score. In the end, Peterson had poor command and was hit hard just like in many of his other starts this season.

Peterson gave up five hits, walked none and struck out two. He improved to 4-6 with the win. Peterson’s Cubs tenure got off to a rocky start when Jackson Chourio homered on the first pitch he threw in Cubs blue. The 30-year-old left-hander was able to settle in and pitch into the sixth inning before handing it off to the bullpen with a 6-2 lead. Peterson has a 5.86 ERA, but his 4.04 xFIP points to a potential bounce back. He’s lined up to face the Cardinals at home next weekend.

It’s a decent spot for Peterson to make his Cubs debut since Milwaukee ranks 22nd as a team in OPS against left-handed pitching this season. The 30-year-old southpaw was acquired from the Mets to shore up Chicago’s injury-ravaged rotation earlier this week. His immediate fantasy appeal is strictly limited to deeper mixed leagues given his struggles this year, but it’s possible a change of scenery helps him get back on track.

Peterson joins a beleaguered Cubs’ rotation to provide some stabilization, but it’s worth noting that he’s been far from a reliable option for most of 2026 with a 6.09 ERA and 1.65 WHIP over his 68 innings with New York prior to the move. The left-hander has had success in the past prior to this year’s scuffles, and because of the litany of injuries to the Chicago staff, he’s going to be given some runway. He should make his debut for the Cubs in the coming days.

Peterson provides Chicago’s injury-ravaged rotation with an immediate injection after struggling to a career-worst 6.09 ERA, 1.65 WHIP and 63/30 K/BB ratio across 68 innings for the Mets this season. The 30-year-old southpaw could certainly benefit from a change of scenery and should get an extended run with the Cubs who lost both Ben Brown (neck) and Edward Cabrera (hamstring) to the injured list earlier this week in addition to missing Cade Horton (elbow) and Jameson Taillon (hamstring) already. The Athletic’s Will Sammon adds that first base prospect Cole Mathis, who has posted a .981 OPS in the lower minors this season, is heading to the Mets in the deal.

Scott is eligible to come off the injured list on Saturday, which would bump Kodai Senga back a couple days or out of New York’s rotation entirely. It’ll be David Peterson handling Friday’s series opener. The 27-year-old will wind up missing only a pair of starts after hitting the injured list with a hip impingement earlier this month. He had allowed three earned runs or fewer in eight consecutive starts prior to being tagged for four runs over 4 2/3 innings by the Cardinals during his last start before landing on the shelf. He boasts a strong 3.10 ERA, 1.35 WHIP and 47/19 K/BB ratio across 40 2/3 innings this season. He’s a decent streaming option for fantasy managers in deeper formats where he may have been dropped.

Peterson walked back-to-back batters to start the game, which set the tone for the evening. The southpaw ran a ton of deep counts and it ultimately cost him. His biggest downfall was a three-run homer off the bat of Kyle Schwarber in the second inning. Peterson struck out five and walked four in the loss and now holds a 6.09 ERA on the year. He didn’t exactly make the case to get more starts in the near future, but the Mets aren’t exactly overflowing with options at the moment.

He’s getting the nod over Tobias Myers, who gave up seven runs in 1 1/3 innings against the Reds on Monday. Peterson last started on May 26, when he surrendered six runs in five innings against the Reds. He has a 5.91 ERA in seven starts and eight relief appearances this season.