The Chicago Cubs endured one of their toughest performances of the season Friday as the St. Louis Cardinals dominated from the opening innings in a one-sided National League matchup. While the entire club struggled to keep pace, newly acquired starter David Peterson experienced an especially difficult afternoon on the mound.
Peterson, who joined Chicago less than two weeks ago in hopes of strengthening an injury-depleted rotation, delivered the roughest outing of his seven-year major league career. The left-hander was unable to slow the Cardinals’ offense, putting the Cubs in an early deficit from which they never recovered.
By the bottom of the sixth inning, Chicago found itself trailing 16-0, reflecting both the Cardinals’ relentless offense and the Cubs’ inability to generate momentum on either side of the ball. Peterson’s outing became the focal point of an afternoon that quickly unraveled for the visitors.
The disappointing performance also raised further questions about Peterson’s adjustment to his new club. After arriving from the New York Mets in late June, the veteran hoped a fresh opportunity would help reverse a difficult season, but his early appearances in Chicago have done little to change that narrative.
1. Cardinals Capitalize on Every Opportunity
Peterson remained on the mound for just 3.2 innings before his afternoon came to an end. During that stretch, the Cardinals consistently put pressure on the Cubs’ starter, combining timely hitting with disciplined plate appearances to build a commanding lead.
The veteran left-hander surrendered nine hits and three walks while striking out three batters. More damaging, however, was the 10 earned runs charged against him, the highest total he has allowed in any game during his major league career.
The Cardinals rarely allowed Peterson to settle into a rhythm. Nearly every mistake over the plate was punished, and Chicago’s pitching staff found itself overwhelmed as St. Louis continued adding runs throughout the contest.
By the time Peterson exited the game, the Cubs faced an enormous deficit with little chance of mounting a comeback. His outing became the defining storyline of a game that quickly slipped beyond Chicago’s control.
2. Trade Has Yet to Produce Immediate Results
The Cubs acquired Peterson from the New York Mets on June 25 in exchange for first base prospect Cole Mathis. The move was intended to provide experienced depth for a starting rotation that had been significantly weakened by injuries.
With five starting pitchers unavailable because of injuries, Chicago’s front office sought a veteran capable of handling regular innings and helping stabilize the rotation during a demanding stretch of the schedule.
So far, that plan has not delivered the desired results. Peterson’s second start for the Cubs became his most difficult outing of the season, adding to concerns that his struggles have continued despite the change of uniform.
Although it remains early in his tenure with Chicago, the organization will be hoping Peterson can quickly rediscover the form that made him an attractive trade target. The Cubs need dependable innings from every available starter as they attempt to navigate the remainder of the season.
3. Difficult Season Marks Sharp Decline
Friday’s outing continued what has already been a challenging 2026 campaign for Peterson. Entering the game, he carried a 5.86 earned run average and a 1.588 WHIP, both representing the highest marks of his career.
Despite recording 65 strikeouts, Peterson has struggled to consistently limit opposing offenses, leading to results well below the standard he established during previous seasons. His inability to command key situations has frequently allowed opponents to capitalize on scoring opportunities.
The decline has surprised many around baseball considering Peterson’s recent success. During the 2024 and 2025 seasons, he developed into a reliable member of the rotation and earned the first All-Star selection of his career after delivering one of the strongest campaigns of his professional career.
For now, both Peterson and the Cubs will look to move beyond Friday’s difficult performance as quickly as possible. While one outing does not define an entire season, Chicago hopes its newest starter can make the necessary adjustments and provide the consistency the club expected when it completed the trade with the Mets.