Shoe-horned: Cubs’ Ben Zobrist irked at MLB threat of fine over all-black cleats

Major League Baseball appears to be taking a page from the NFL by cracking down on violations of uniform rules, specifically shoe color.

And the Cubs’ Ben Zobrist isn’t happy about it, calling it ‘‘ridiculous.’’

On his Instagram account Saturday, Zobrist posted a copy of a warning letter he received about the all-black shoes he has worn for the last two years during home day games without comment from MLB.

Alongside the letter, which threatened fines for continued violations, he wrote an appeal to MLB that began: ‘‘Dear @mlb, I still like you, but this is ridiculous.’’

The rule cited in the letter stipulates that at least 51 percent of the shoe color be the team’s designated color — in this case, blue.

Zobrist wrote he wore the black shoes ‘‘to pay homage to the history of our great game,’’ describing the way he was inspired as a kid by highlights of greats such as Ernie Banks and Stan Musial with their ‘‘old uniforms and all-black cleats with flaps.’’

‘‘I am curious as to why @mlb is spending time and money enforcing this now when they haven’t done it previously in the last year and beyond,’’ he said.

Zobrist said he didn’t want to discuss the matter with reporters until he gets more information about the subject. But the letter didn’t stop him from wearing the black shoes when he entered the game against the White Sox on a double switch in the ninth inning.

‘‘I’m going to talk to the union and MLB about it to find out more,’’ said Zobrist, who won’t have the issue Sunday because of MLB’s pink shoes and bats for Mother’s Day.

Indians pitcher Mike Clevinger received a similar warning for ‘‘non-conforming shoes’’ and Friday tweeted an excerpt from the letter and his comments: ‘‘Make baseball fun again, they said, it would be fun, they said.’’

When contacted for comment, MLB issued a statement citing the shoe regulations in the collective bargaining agreement.

‘‘If players have complaints about the regulations, they should contact their union, which negotiated them,’’ the statement reads. ‘‘We have informed the union that we are prepared to negotiate rules providing players with more flexibility, and that issue is currently being discussed as part of a larger discussion about apparel and equipment.’’

Cubs manager Joe Maddon, who once had to appeal to MLB to be allowed to wear a hoodie in the dugout, has Zobrist’s back.

‘‘I love the shoes that he’s wearing, and the reason that he gave was outstanding,’’ Maddon said. ‘‘I’m right on board with it, absolutely.’’

Workload watch

The Cubs are two games into a stretch of 11 games in 10 days, including a doubleheader next Saturday in Cincinnati. That makes the 7 1/3 innings the bullpen has worked the last two days a factor as Kyle Hendricks starts the series finale Sunday against the Sox.

Hendricks has made a habit in his career of making deep starts after heavy bullpen use, including pitching eight innings in his last start after back-to-back extra-inning games.

‘‘You have it in the back of your mind, for sure,’’ Hendricks said of those starts.

“If players have complaints about the regulations, they should contact their union which negotiated them,” the statement reads. “We have informed the union that we are prepared to negotiate rules providing players with more flexibility, and that issue is currently being discussed as part of a larger discussion about apparel and equipment.”