Despite the ex-Bayern Munich boss' confidence, it was hard not to raise an eyebrow when Havertz trudged over to the left wing at the Olympiastadion in Berlin to take his place alongside Jonathan Tah, Antonio Rudiger and Benjamin Henrichs in the back four.
However, inside five minutes, the Arsenal man had scored, sweeping home Leroy Sane's cross after the ball broke from a set-play. It was a nice moment, especially considering how badly Havertz has struggled in front of goal since joining the Gunners, but it told us little about how he might fare as a left-back long-term.
As the game progressed, though, there were a few promising signs in this regard. Havertz scampered forward each time Germany were in possession, generally staying wide as opposed to coming inside, as is all the rage in the Premier League currently.
Despite this attacking intent, he was not culpable for either of Turkey's first-half goals, matching up well against his opposite number. The blame for each of those must instead be apportioned to right-back Henrichs, whose positioning was lax for both strikes.
Turkey's third, however, scored after Niclas Fullkrug had levelled the scores up in the 49th minute, did involve Havertz. He was penalised for handball in the box, rather unfortunately, when his arm was deemed to have been in an 'unnatural position' when it blocked Abdulkerim Barakci's volleyed cross. Yusuf Sari would then dispatch the resulting penalty.
That moment aside, Havertz enjoyed a pretty solid first outing in his new role. He got up and down the wing, though his defensive positioning was a little suspect at times, and made a team-high five clearances, as well as registering two interceptions. He got on the ball far more frequently than he has been for his club recently too, registering more touches (63) than he's managed in all-but one of his Arsenal appearances so far.
Nagelsmann was certainly impressed, saying at full-time: "Kai said he wanted to do it, wanted to try it. I don't see this as a risk for him, but as a very, very big opportunity to play a key role at the Euros. For a first time in an unfamiliar position, he did extremely well and probably was our best player."