The Cubs' excellent throwback unis caused a brief wardrobe problem for starter Eddie Butler

The Pirates held their annual "Negro Leagues Heritage Game" against the Cubs on Friday night at PNC Park, which could only mean one thing: some truly stellar throwback uniforms. And long before the Cubs scored six in the ninth for a wild 9-5 win, the uniforms provided an interesting moment.

Pittsburgh wore the uniforms of the Homestead Grays, while Chicago chose to honor the Leland Giants -- the first African-American team to ever play the Cubs, way back in 1909.

As you can see from the photo above, Chicago's uniforms came complete with white long-sleeve shirts to be worn underneath the jersey itself. Which is all well and good ... except, per MLB rules, pitchers aren't allowed to have any white on their sleeves while on the mound -- it would make it too difficult for batters to pick up the ball.

So, when Cubs starter Eddie Butler took the mound in the bottom of the first, he immediately had to call for a pair of scissors:

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Butler was perfectly aware of the rule, and was ready for the impromptu tailoring. "I was not surprised at all," he told MLB.com's Carrie Muskat after Chicago's victory. "[Home plate umpire Will Little] came out before I finished the warm up pitches, and said, 'You're not going to be able to have that.' You're not going to be allowed to wear a white sleeve."

Still, it was worth a shot: "We had to go out there and see what we could do with it, have some fun with it. We figured it wasn't going to last long. We might as well try."

Of course, that might not have even been the wildest part of the first inning: In the top half, Anthony Rizzo 's bid for a third straight leadoff homer drifted just foul, and Joe Maddon was eventually ejected arguing the call.