Mets reportedly trading David Peterson to Cubs, with Cole Mathis returning to New York

What happened

The Cubs are acquiring starting pitcher David Peterson from the Mets, per Jeff Passan of ESPN, with minor league first baseman Cole Mathis going to New York in return, per Will Sammon of The Athletic. Neither club had issued a formal announcement as of the reporting, and details beyond the two players involved had not been provided by either organization.

The deal is reportedly taking shape in the middle of an ongoing four-game series between the two clubs at Citi Field — which, as baseball scheduling occasionally reminds us, is a perfectly normal place to finalize the paperwork on sending someone to the other dugout.

Why it matters

The Cubs arrive at this deal carrying rotation injuries, and the need for depth arms had not been a quiet internal matter. President of baseball operations Jed Hoyer said the day before the report emerged that the front office was actively exploring the trade market for pitching depth. Peterson, a left-handed starter, would address that need directly, per the reporting.

For the Mets, the calculus is harder to look at. The series against Chicago had not gone well heading into the report: the Cubs had taken the first three games, including sweeping a doubleheader on the same day by scoring a combined 20 runs. A six-error performance in game two of that twin bill represented one of the more difficult moments in what MLB Trade Rumors described as a dreadful season for New York. The Mets dropped 12 games under .500 for the first time since 2023 during this stretch. Trading a rotation piece mid-series, mid-collapse, is the kind of move that tends to get remembered — though whether it gets remembered as a pivot or a surrender is a question the standings will eventually answer.

Mathis, the return piece, is a minor league first baseman. MLB Trade Rumors does not provide additional detail on his level or statistical profile beyond his position and organizational assignment.

Where the club stands

The Cubs enter this reported deal at 89-73 (.549), sitting 2nd in the NL Central, 14 games back in the division. That division gap is, for practical purposes, closed — they have been eliminated from the division race. Their path forward runs through the Wild Card, where they currently rank 2nd and sit +1.0 relative to the cut line. They arrive on a one-game winning streak heading into Thursday's series finale.

### Is Peterson already in the Cubs' rotation plans?

The Cubs' probable pitcher listing for Saturday, June 27, against the Milwaukee Brewers at American Family Field shows David Peterson opposed by Kyle Harrison. That scheduling detail, taken alongside the timing of the report, suggests Chicago is moving quickly to integrate Peterson into active rotation plans — though the formal roster mechanics of the move had not been detailed in the reporting as of MLB Trade Rumors' final update.

Before that, the Cubs close out the current series Thursday, June 25, at Citi Field — still against the Mets — with Matthew Boyd listed as the probable against Freddy Peralta. Then it's Friday, June 26, in Milwaukee, where Colin Rea is slated to face Jacob Misiorowski.

The back half of that stretch — two games in Milwaukee followed by a Peterson start — represents exactly the kind of schedule that makes rotation depth feel urgent. The Brewers sit in the same division, and a Wild Card margin of +1.0 relative to the cut line is not the kind of cushion that invites complacency about who is taking the ball every fifth day.

For the Mets, the rotation picture after this reported deal is less clear. MLB Trade Rumors does not detail what New York's rotation looks like with Peterson gone, and no replacement has been reported.

What we don't know yet

As of MLB Trade Rumors' final update, neither the Cubs nor the Mets had issued a formal announcement. The financial terms of the deal — any remaining salary, contract status, or service time considerations — have not been reported. Mathis's minor league level, statistical profile, and organizational standing beyond his position are not detailed in the reporting.

It also remains unreported whether the roster moves required to complete the transaction — adding Peterson to Chicago's 40-man roster, clearing a corresponding spot, and formally placing him on the active roster — have been processed. Under general league mechanics, a pitcher joining an active roster via trade requires the receiving club to have 40-man space and an open active roster spot, but MLB Trade Rumors does not specify how the Cubs intend to handle those logistics.

What to watch

The Saturday probable listing is the most immediate thing to track. If Peterson takes the ball against the Brewers on June 27 as listed, that would represent the Cubs moving quickly to put the reported acquisition to work in a divisionally meaningful game. Whether that start is formally announced by the club, and what roster move accompanies it, will fill in the gaps the current reporting leaves open.

For the Mets, the question is what Mathis represents in the broader organizational calculus — a lottery ticket at first base, a depth piece, or something else entirely. MLB Trade Rumors does not offer a frame for that, and the desk will not supply one. What the reporting does make clear is that New York is 12 games under .500 and in the middle of a series it had lost three straight games of, which is the kind of context that tends to make front offices reach for the trade market whether or not the timing feels tidy.

The Cubs, meanwhile, are a team that needed pitching, said so publicly the day before this report landed, and now reportedly have a left-handed starter joining a rotation that has been dealing with injuries. The Wild Card margin is real but not comfortable. The schedule ahead is not soft. And Peterson, per the probable listings, is already penciled in for Saturday.

Baseball, as ever, does not wait for the paperwork to dry.