I am well aware that Josê Quintana is kind of a hot-button topic around these parts, given what was traded away for him and his relative lack of performance as a Cub.
I do want to point out that Quintana was having a pretty good year in 2019 through the end of August: 27 games (26 starts), 3.90 ERA, 1.280 WHIP, 3.69 FIP — probably would have been about a 2 WAR season if that had continued.
Instead, Q’s September 2019 was disastrous: Five starts, 11.09 ERA, 2.250 WHIP — and the Cubs actually won two of those games.