Key Cubs deadline pickup has continued to struggle when the team needs him most

After another 0-for-4 performance in Sunday's loss to the Colorado Rockies, Chicago Cubs' utility man Willi Castro is starting to look like a liability at the plate.

When the Cubs traded for Castro at this year's deadline, the 28-year-old was enjoying a decent season with the bat. In 344 plate appearances for the Minnesota Twins, Castro launched 10 homers and slashed .245/.335/.407. Not bad for a guy whose main contribution is his defensive versatility.

But Castro's production has taken a nosedive since coming to Chicago. It's getting bad enough that it will be hard to justify giving him starts in September or even a roster spot in the playoffs if he continues on this trajectory.

Castro has posted an unbelievably bad OPS (.404) and wRC+ (7), adding him to the list of disappointing performances from this year's trade deadline acquisitions. Entering Tuesday night's game against Atlanta, Andrew Kittredge has a 4.15 ERA in 13 innings, Taylor Rogers owns a 6.52 ERA in 9.2 innings, and Michael Soroka threw two innings before hitting the injured list with a shoulder strain. Castro's disappointing numbers just add to the pain of this year's frustrating trade deadline.

What do the Cubs do with Willi Castro moving forward?

At this point, Castro should only be utilized as a defensive replacement late in games where the score isn't close. The Cubs offense can't afford to have another dead spot with the lineup struggling to score runs and so many starters slumping at the same time.

It would be different if the Cubs were safely holding first place like the Milwaukee Brewers are right now. But every game and at-bat matters right now, and the Cubs need to put their best players on the field to crack the playoffs this year. The silver lining is that Castro can play almost every position on the field if someone needs a day off. But those days off shouldn't be a daily thing, and the days of Castro getting starts at third base over Matt Shaw should be a thing of the past. Whether the team actually does that or not remains to be seen.