Michael Busch's breakout has rendered this Cubs clubhouse favorite superfluous

Michael Busch is coming off a record-setting weekend, and he's surged into first place on the team in OPS (.939) and wRC+ (162) heading into Sunday's game against the rival St. Louis Cardinals.

However, the highlight of his performance wasn't the fireworks-inducing three-homer game on July 4. Instead, drawing a rare start against a southpaw on Saturday, Busch smoked two extra-base hits against Matthew Liberatore, including another blast to the bleachers.

Busch made his case after the game to start against more southpaws going forward. It would require a demotion — if not outright roster replacement — of Justin Turner to make that happen, but it's clear the Cubs would be better for it.

Michael Busch is pushing Justin Turner into a full-time bench role

The front office's idea of platooning Busch and Turner at first base prior to the season made a lot of sense on paper.

In his career, Busch is slashing .227/.295/.360 against lefties, compared to Turner's .275/.358/.458. That 161 point difference in OPS is massive, and more than enough to warrant platooning the two despite Michael Busch's far better defensive metrics at first base.

However, this season, Busch is hitting .174/.255/.348 (70 wRC+) against southpaws. That's obviously worse than his career line, but he's been much-improved recently, and the sample size on that is just 51 plate appearances. Another big game against a lefty like he had on Saturday could push his line into league-average territory.

More importantly, though, is that Turner is hitting just .268/.317/.357 (90 wRC+) against lefties this season, a steep drop-off from his usual standards. That's obviously been a running theme for Turner this year, as he swings the slowest bat in baseball and is simply unable to hit the ball as hard as he once was.

Because Turner is no longer a capable glove at third base — and really can't play anywhere else besides first base — there's an obvious for incentive for Craig Counsell to get him in the lineup at the cold corner against lefties, especially since he is technically hitting them better than Busch is this year.

But, like most athletes, Busch gets better with more reps. As he's facing more lefties this season, he's hitting them better, and his long-term development as an everyday first baseman is at least just as important than whatever (extremely marginal) additional impact Turner can provide at the plate. Plus, with the offensive gap shrinking between them, Busch's far better glove work arguably makes him a more valuable asset to have in the lineup anyway.

All of this is to say: Turner's presence on this team has always been more about his championship experience than his declining production. Of all the team's porous bench options, he's absolutely the best. But, with Busch emerging as one of the best first basemen in baseball, perhaps it's best to keep Turner on the bench moving forward.