Among the top rental pitchers the Chicago Cubs could acquire at the MLB trade is Seth Lugo of the Kansas City Royals. Lugo isn't a traditional rental, considering he does hold a $15MM player option for the 2026 season. Assuming health, it seems like a foregone conclusion that Lugo will test free agency, given the success he has had over the last two seasons.
That said, the $15MM player option can be viewed as a burden, considering a significant injury during the closing months of the season would make that a mere formality, and the Cubs would take a significant financial hit to the money they have available this offseason.