Hats off to Colin Rea, who has done an admirable job filling in for the Cubs in the starting rotation, but as the 2025 season progresses we’re seeing the biggest flaw on the team being exposed. Fans have been frustrated by the bullpen performance, but the starting rotation is actually the major red flag on this roster.

Rea was hammered by the Reds for the second consecutive start within a week. The right-hander gave up a leadoff homer to TJ Friedl to begin the game and you knew early on it wasn’t going to be pretty for Rea. Despite limiting the damage to two runs in the first, all five balls that were put in play by the Reds against Rea had an average exit velocity of at least 99mph.

Cincinnati proceeded to hit a pair of two-run homers against Rea that put the Cubs behind 6-0 after the sixth inning. Rea exited after 5.2 innings, all six runs were earned on 10 hits, including three home runs.

Rea began the season in the bullpen, but was bumped up into the starting rotation after Justin Steele was sidelined with an arm injury. The 34-year-old recorded a 2.72 ERA in seven starts from April 13 through May 18.

However, things have been going south for Rea for a bit. Friday’s start against the Reds marked the sixth straight game in which he’s allowed a home run. That was after giving up zero home runs in his first 18.2 innings of the year.

But it’s not just Rea who has regressed. Ben Brown hasn’t been the pitcher the Cubs saw in 2024. The 25-year-old has been getting lit up in May and hasn’t posted a quality start since May 2.

Injuries have obviously effected the Cubs’ rotation so far in 2025. Steele is out for the year and Shōta Imanaga has been out since May 4, with a hamstring injury. The Cubs desperately need Imanaga back and quite frankly even with his return this team should be trying to add another quality starter via the trade market.

The Cubs’ starting rotation had the fifth-best ERA through Imanaga’s last start. Since then, the starters have pitched to an ERA north of five. That includes Friday’s 6-2 loss to the Reds. Meanwhile, the bullpen has actually come around and has become a strength for Craig Counsell.

Imanaga is still a few weeks away from coming back, so the Cubs have to find a way to make it work until then. That means a couple more starts from Rea and experimenting with openers.

The Cubs did a great job of emerging from the toughest schedule to open the season with a winning record. They bought themselves a bit of wiggle room, but if this team has serious intensions of competing in 2025, then Jed Hoyer and co. must address the starting rotation.