WATCH: Shapovalov talks coffee during coaching changeover

Of all the innovations introduced at the Next Gen ATP Finals—a shot clock, no lets, Hawk-Eye line judges, etc.—the one getting the most attention, shockingly, is headset coaching.

It's received copious praise, and criticism, for many reasons, but one fun side effect is that fans get to eavesdrop on the non sequiturs. There was Alexander Zverev disparaging Marcelo Melo during his exhibition match and on Thursday came an exchange between Denis Shapovalov and Martin Laurendeau on the quality and price of coffee in Milan.

"Dude, I'm telling you, best coffee I've ever had in my life—best coffee I've ever had. It was a joke," Shapovalov said. "I got two cappuccinos, he got a cappuccino and an espresso, and I got a croissant. Six euros. It was a joke."

And that endorsement comes from a place of expertise. As ATP Challenger tour commentator Mike Cation can attest, Shapovalov is quite the coffee connoisseur.

The Canadian and his coach later used the headsets to talk about the "sick" in-house beats.

Though Shapovalov ended up getting eliminated from the Next Gen ATP Finals with a fifth-set tiebreak loss to Andrey Rublev, he was named the ATP's Most Improved Player of 2017 the very same day.

Since January, the teenager has risen from No. 250 to finish the season as No. 51.