(CBS) Given their likely path to a coin flip win-or-go-home one-game playoff, the Cubs understandably didn’t go all in on the 2015 season ahead of the July 31 non-waiver trade deadline. Instead of giving up a horde of promising prospects for an ace like Cole Hamels, Chicago simply made a quiet move, acquiring right-hander Dan Haren from Miami to be its No. 5 starter.

The move hasn’t worked out well. Haren’s been no better than Chicago’s rotating cast of No. 5 starters earlier in the season. In five starts for the Cubs, Haren has compiled a 6.31 ERA and 1.44 WHIP across 25 2/3 innings. Haren’s mark is 1-2 in Chicago, while the team is 2-3 in those games, including a 9-7 win against Atlanta in which Haren didn’t make it out of the fifth inning.

On Thursday, Haren gave up five runs, all earned, in 6 1/3 innings in a 9-1 loss at San Francisco. He probably would’ve been pulled far earlier if not for the Giants taking control early and ace Madison Bumgarner rolling, as Cubs manager Joe Maddon could see the writing on the wall of his team fighting an uphill battle and the smart decision being to get his bullpen some rest.

Thursday marked the first time Haren had made it out of the sixth inning as a Cub. Given his struggles, he’s on track to pitch himself off the postseason roster, should the Cubs make it there.

Teams only need four starters in a postseason series, so the Cubs would trot out Jon Lester, Jake Arrieta, Jason Hammel and Kyle Hendricks. As of now, it’s hard to see what value Haren brings to the Cubs, who have Travis Wood and Clayton Richard to handle long-relief duties. Plus, the acquisition of Fernando Rodney adds another arm to the bullpen.

The 34-year-old Haren has big-game experience — recording a combined 3.26 ERA in postseason appearances in 2004 and 2006 — but he has to turn it around big time to have a chance to contribute in the postseason.