The Chicago Cubs would trade No. 1 prospect Owen Caissie to pry pitcher Mitch Keller from the Pittsburgh Pirates. At least that’s the latest buzz circulating the baseball world, as reported by Bob Nightengale of USA Today and echoed, in more of a speculative fashion, by Ken Rosenthal of The Athletic.

Rumor: Cubs Would Trade Owen Caissie for Mitch Keller
That the Cubs are now entertaining trading Caissie is, in the words of the great Groucho Marx, “the most unheard thing I ever heard of.” Noah Hiles of the Pittsburgh Post-Gazette recently reported that Keller was more of a backup plan for the Cubs. Whatever Plan A was must have fallen through. Furthermore, with the Cubs tied atop the National League Central Division with the hard-charging Milwaukee Brewers entering Sunday’s schedule, there may be more desperation emanating from Wrigley Field. With three other teams rumored to be in the Keller sweepstakes as of last Tuesday, the Cubs might feel a need to sweeten the pot with Caissie.
Trade deadline updates, per @BNightengale:
• White Sox want Mark Vientos from the Mets in any deal for Luis Robert Jr.
• Cubs are targeting Mitch Keller and would include prospect Owen Caissie
• Jhoan Duran, David Bednar, Ryan Helsley believed to be 3 best relievers traded
•…— Underdog MLB (@UnderdogMLB) July 27, 2025
Keller, 29, is arguably the top prize available among starting pitchers. His 4-10 record won’t excite Cubs fans who still believe that to be the measure of a pitcher. But he also boasts a 3.53 ERA to go with a 3.42 FIP, 1.160 WHIP, and 3.23 strikeout-to-walk ratio. He’s walked just 5.8 percent of batters faced and held opponents to a .239/.290/.363 slash line. Keller has now pitched into the sixth inning in 14 straight starts, giving up more than three runs in only one of those starts. Over that time, his ERA is 3.14. He’s kept the ball in the ballpark, too, surrendering just 10 home runs to the 519 batters he’s faced. His home run percentage would likely increase, however, once he leaves cavernous PNC Park for the friendly confines of Wrigley. Hiles recently gave Keller a 75 percent probability of being dealt by the deadline.
Caissie Would Provide a Much-Needed Bat
For what it’s worth, the Baseball Trade Values site computes that Keller is “worth” Caissie and the Cubs’ No. 3 prospect, infielder Jefferson Rojas. However, there are no credible rumors connecting Rojas to the Pirates.
Caissie, 23, is a six-foot-three, 190-pound left-handed-hitting outfielder. The last Canadian to patrol the Pirates outfield, Jason Bay, didn’t work out too badly for them. The San Diego Padres drafted Caissie in the second round of the 2020 June Amateur Draft out of high school in Burlington, Ontario. That’s the highest a Canadian was ever chosen in the history of the draft. The following December, the Padres included him in a trade with the Cubs to land Yu Darvish and Victor Caratini. At Triple-A Iowa this season, Caissie is hitting .278/.377/563, 20 HR, and 46 RBI. That’s consistent with last year’s .278/.375/.472, 19 HR, and 75 RBI at Iowa. He’s a fast runner despite low stolen base totals. On the scouting scale of 80, scouts give him a 60 rating for power. They see 30 home run potential in Caissie.
The Last Word
Some might question the wisdom of a Caissie-for-Keller trade, given that each club would be strengthening a division rival for several years to come. Keller is in the second year of a contract extension that ties him up through 2028. Meanwhile, Caissie, of course, who’s yet to make his major league debut, hasn’t started his service time clock yet. The Cubs, with their superior resources, are likely less concerned about that.
The Pirates apparently aren’t concerned, either. Their fans will recall a major trade with the St. Louis Cardinals on April Fool’s Day, 1987. That’s when the Pirates sent catcher Tony Peña to their NL East Division rival in exchange for Andy Van Slyke, Mike LaValliere, and Mike Dunne. St. Louis won the NL pennant in 1987, and the Pirates won division titles from 1990-92. That deal worked out well for both parties. In any event, interdivisional trades may be less of a concern throughout baseball under the present Wild Card system. How many such trades are executed this week will be interesting to see.
Main Photo Credit: © Cody Scanlan/The Register / USA TODAY NETWORK via Imagn Images
The post Rumor: Cubs Would Include No. 1 Prospect in Deal for Mitch Keller appeared first on Last Word On Baseball.